TWI683088B - Substrate inspection device, substrate processing apparatus, substrate inspection method and substrate processing method - Google Patents

Abstract

Generate actual image data representing the image of one side of the substrate. On the image based on the actual image data, a plurality of unit areas arranged in the first diameter direction of the substrate are set. For each of the plurality of unit areas, the average value of the plurality of pixels constituting the unit area is calculated as the average pixel value, and the average pixel value of the plurality of unit areas is smoothed. Calculate the difference between the smoothed average pixel value of a predetermined unit area and the average pixel value of each unit area after smoothing. Each pixel value in the band-shaped region extending parallel to the second diameter direction orthogonal to the first diameter direction from each unit area is added to the difference corresponding to the unit area to generate image data for display.

Description

Substrate inspection device, substrate processing device, substrate inspection method and substrate processing method

The present invention relates to a substrate inspection device, a substrate processing device, a substrate inspection method, and a substrate processing method that perform substrate inspection.

In the substrate processing apparatus, the substrate horizontally supported by the rotating chuck is rotated. In this state, by spraying a coating liquid such as a resist solution onto the central portion of the upper surface of the substrate, a coating film is formed on the entire surface of the substrate. By exposing the coating film and developing it, a specific pattern is formed on the coating film. Here, if the surface of the substrate is in a non-uniform state, the state after exposure will fluctuate in each part of the substrate, resulting in poor processing of the substrate. Therefore, the surface condition of the substrate may be checked.

Patent Document 1 describes an inspection device that macroscopically inspects samples such as semiconductor wafers. In this inspection device, the sample placed on the stage is irradiated with illumination light extending linearly in the X direction parallel to the surface of the sample, and the light reflected from the linear region on the surface of the sample is imaged on the detector by the imaging lens (Line sensor camera) light receiving surface. By moving the stage in the Y direction orthogonal to the X direction and parallel to the sample surface, the light reflected by the plurality of linear regions on the sample surface is captured by the detector. By this, the entire image of the sample surface is generated. Determine the quality of the sample based on the brightness value of the generated image.

[Patent Document 1] Japanese Patent Laid-Open No. 2015-127653

[Problems to be solved by the invention]

According to the inspection device described above, visual inspection can be performed using the image of the sample generated by imaging. However, in the image of the sample generated by the camera, there are actually a plurality of parts that should be expressed in the same color, brightness, or density in different colors, brightness, or density. In this case, it is difficult to determine whether there is a defect in the surface condition of the sample on the image.

An object of the present invention is to provide a substrate inspection device, a substrate processing device, a substrate inspection method, and a substrate processing method. In a visual inspection using an image of a substrate, a user can easily and accurately determine the presence or absence of a defect. [Technical means to solve the problem]

(1) A substrate inspection apparatus according to one aspect of the present invention includes: a holding portion that holds a substrate; an imaging portion that captures a surface of the substrate held by the holding portion and generates an actual image representing an image of the substrate surface Data; a smoothing unit, which calculates the average pixel value of each of the plurality of unit areas that constitute the unit area on the image based on the actual image data for each of the plurality of unit areas arranged in the first diameter direction of the substrate , Smoothing the average pixel value of the plurality of unit areas; and the correction section, which calculates the average pixel value after smoothing of the predetermined unit area in the plurality of unit areas and the smoothing processing of each unit area The average pixel value difference is added to each pixel value in the band-shaped region extending parallel to the second diameter direction orthogonal to the first diameter direction from each unit region.

In this substrate inspection device, actual image data representing an image of one side of the substrate is generated by photographing one side of the substrate held by the holding portion. For each of the plurality of unit areas, the average value of the plurality of pixels constituting the unit area is calculated as an average pixel value, and the average pixel value of the plurality of unit areas is smoothed.

Calculate the difference between the average pixel value after the smoothing process of the predetermined unit area in the plurality of unit areas and the average pixel value after the smoothing process of each unit area. To each pixel value in the band-shaped region extending parallel to the second diameter direction from each unit region, a difference corresponding to the unit region is added. In this way, in the image based on the corrected actual image data, the average value of the plurality of pixels in each strip-shaped area is equal to or approximately equal to the average pixel value of the predetermined unit area. Therefore, in the image based on the corrected actual image data, it is suppressed that the average color of the plural portions of one surface of the substrate regarded as the first diameter direction is different. As a result, in the visual inspection using the image based on the corrected actual image data, the presence or absence of defects in the surface state of the substrate can be easily and accurately determined.

(2) The smoothing process may also be a smoothing process using the moving median method.

In this case, by using the smoothing process of the moving median method, the fluctuation of the local average pixel value is appropriately reduced.

(3) On a surface of the substrate, a film formed with a periodic pattern in the first diameter direction may have a width that is greater than the period of the pattern in the first diameter direction by the smoothing process using the moving median method.

In this case, the fluctuation of the average pixel value due to the pattern of the film formed on one surface of the substrate is appropriately reduced.

(4) Each pixel constituting each of the plurality of unit areas includes R pixels, B pixels, and G pixels, and the smoothing unit may also perform smoothing processing for each pixel type, and the correction unit performs plural differences for each pixel type The calculation process is performed, and a plurality of differences are added for each pixel type.

In this case, it is considered that the average hue of a plurality of parts of one surface of the substrate in the first diameter direction is different on the image based on the corrected actual image data.

(5) A substrate inspection device according to another aspect of the present invention includes: a holding portion that holds a substrate; an imaging portion that takes a picture of a surface of the substrate held by the holding portion and generates an actual image representing an image of the substrate surface Image data; a smoothing unit, which calculates the average of the plurality of pixels constituting the unit area as the average pixel for each of the plurality of unit areas arranged in the first diameter direction of the substrate on the image based on the actual image data Value, the first smoothing process using the moving median method is performed on the average pixel value of a plurality of unit areas; the deviation calculation unit calculates the average pixel value before the first smoothing process of each unit area and the first smoothing process The difference between the average pixel values afterwards is used as the deviation; the deviation maximum value calculation unit calculates the plural deviations after the second smoothing process by performing the second smoothing process using the moving maximum method on the deviations of the plural unit regions As a plurality of deviation maximum values; a deviation minimum value calculation unit that calculates the plurality of deviations after the third smoothing process as the plurality of deviations by performing the third smoothing process using the moving minimum method on the deviations of the plurality of unit areas The minimum value; the difference maximum value calculation unit, which calculates the sum of the average pixel value after the first smoothing process of each unit area and the deviation maximum value as the maximum difference value; the difference minimum value calculation unit, which calculates each The sum of the average pixel value after the first smoothing process of the unit area and the minimum deviation value is taken as the minimum difference; the reference range determination unit determines the minimum difference to the maximum difference corresponding to the predetermined unit area The range of values is used as a reference range; and a correction section that corrects the range corresponding to each unit area from the minimum difference to the maximum difference with the reference range, and to make the unit area orthogonal to The pixel values in the band-shaped regions extending in parallel in the first diametric direction and the second diametric direction are corrected in a manner suitable for the corrected range.

In this substrate inspection device, actual image data representing an image of one surface of the substrate is generated by photographing one surface of the substrate held by the holding portion. For each of the plurality of unit areas, the average value of the plurality of pixels constituting the unit area is calculated as the average pixel value, and the average pixel value of the plurality of unit areas is subjected to the first smoothing process using the moving median method. In this case, the fluctuation of the local average pixel value is appropriately reduced.

The difference between the average pixel value before the first smoothing process and the average pixel value after the first smoothing process in each unit area is calculated as a deviation. The second smoothing process using the moving maximum method is performed on the deviations of the plurality of unit areas, and the plurality of deviations after the second smoothing process is calculated as the maximum value of the plurality of deviations. In addition, the third smoothing process using the moving minimum method is performed on the deviations of the plurality of unit areas, and the plurality of deviations after the third smoothing process is calculated as the minimum value of the plurality of deviations.

The maximum difference is calculated by adding the average pixel value after the first smoothing process of each unit area to the maximum deviation, and by the average pixel value after the first smoothing process of each unit area and the minimum deviation The values are added to calculate the minimum difference.

The range from the minimum value to the maximum value of the difference corresponding to the predetermined unit area is determined as the reference range. The correction is made so that the range corresponding to the minimum difference to the maximum difference of each unit area is consistent with the reference range, and the pixel values in each band-shaped area extending parallel from each unit area in the second diameter direction are suitable Make corrections within the revised range. In this way, in the image based on the corrected actual image data, the average value of the plurality of pixels in each strip-shaped area is equal to or approximately equal to the average pixel value of the predetermined unit area. In addition, each pixel value in each band-shaped area is expressed so as to fit within the reference range. Therefore, in the image based on the actual image data after the correction, the average color of the plural portions of one surface of the substrate viewed in the first diameter direction is suppressed from being different. As a result, in the visual inspection using the image based on the corrected actual image data, the presence or absence of defects in the surface state of the substrate can be easily and accurately determined.

(6) On a surface of the substrate, a film having a periodic pattern in the first diameter direction is formed by the first smoothing process using the moving median method, the second smoothing process using the moving maximum method, and the one using the moving minimum method The width used for the third smoothing process may be greater than the period of the pattern in the first diameter direction.

In this case, the fluctuation of the average pixel value, the maximum deviation value, and the minimum deviation value due to the pattern of the film formed on one surface of the substrate is appropriately reduced.

(7) Each pixel constituting each of the plurality of unit areas may include R pixels, B pixels, and G pixels, the smoothing unit performs the first smoothing process for each pixel type, and the deviation calculation unit performs for each pixel type The calculation process of a plurality of deviations, the deviation maximum calculation unit performs the calculation process of a plurality of maximum differences for each pixel type, and the deviation minimum calculation unit performs a calculation process of a plurality of minimum differences for each pixel type, difference The amount maximum calculation unit performs calculation processing of a plurality of difference maximum values for each pixel type, the difference minimum calculation unit performs calculation processing of a plurality of difference minimum values for each pixel type, and the reference range determination unit For the pixel type, the reference range is determined, and the correction section performs correction processing for each pixel type to make the range corresponding to the minimum value of the difference between each unit area and the maximum value of the difference coincide with the reference range, and to make each band area Each pixel value is suitable for the correction process of the corrected range.

In this case, it is considered that the average hue of a plurality of parts of one surface of the substrate in the first diameter direction is different on the image based on the corrected actual image data.

(8) The smoothing unit may also calculate the average pixel value for each of the unit regions located at one end of the first diameter direction of the substrate on the part of the plurality of unit regions, that is, the image based on the actual image data, Based on the estimation of the plurality of average pixel values calculated for the plurality of unit regions located at the portion adjacent to the one end, the plurality of average pixel values corresponding to the plurality of unit regions located at one end are determined based on the estimation result.

According to the above configuration, the plurality of average pixel values of the plurality of unit regions at one end of the substrate on the image based on the actual image data are based on the average pixel values of the plurality of unit regions at the portion adjacent to the one end And presumed. Based on the estimation result, it is determined that a plurality of average pixel values corresponding to a plurality of unit regions at one end, respectively. By this, it is suppressed that the average color at one end of the substrate in the image based on the corrected actual image data is significantly different from the average color at the portion adjacent to the one end.

(9) The imaging section may have a linear imaging area that extends parallel to the first diameter direction on one surface of the substrate held by the holding section, and the substrate inspection device further includes a moving section so that the imaging area is at the second In the diameter direction, the imaging unit and the holding unit are relatively moved by one surface of the substrate held by the holding unit.

In this case, the actual image data representing the entire image of one surface of the substrate is generated by the relative movement of the imaging unit and the holding unit. Therefore, the enlargement of the imaging unit is suppressed.

(10) A substrate processing apparatus according to still another aspect of the present invention includes: a coating processing section that forms a film on one surface of the substrate by supplying a processing liquid to one surface of the substrate; the above-described substrate inspection apparatus, which Inspecting a substrate formed with a film by a coating processing section; and a conveying device that conveys the substrate between the coating processing section and the substrate inspection device.

In this substrate processing apparatus, the surface state of one surface of the film-formed substrate is inspected by the above substrate inspection apparatus. Thereby, in the visual inspection using the image representing one side of the substrate, the presence or absence of defects of the film formed on one side of the substrate can be easily and accurately determined. As a result, the occurrence of defective processing of the substrate is reduced.

(11) According to still another aspect of the present invention, the substrate inspection method includes the following steps: photographing one side of the substrate held by the holding portion, and generating actual image data representing an image of one side of the substrate; Each of the plurality of unit areas arranged in the first diameter direction of the substrate on the image of the data, calculates the average value of the plurality of pixels constituting the unit area as the average pixel value, and smoothes the average pixel value of the plurality of unit areas Processing; and calculating the difference between the average pixel value after the smoothing process of the predetermined unit area in the plurality of unit areas and the average pixel value after the smoothing process of each unit area, and for each unit area to be orthogonal to Each pixel value in the band-shaped region extending parallel to the second diameter direction in the first diameter direction is added to the difference corresponding to the unit area.

In this substrate inspection method, actual image data representing an image of one surface of the substrate is generated by photographing one surface of the substrate held by the holding portion. For each of the plurality of unit areas, the average value of the plurality of pixels constituting the unit area is calculated as an average pixel value, and the average pixel value of the plurality of unit areas is smoothed.

Calculate the difference between the average pixel value after the smoothing process of the predetermined unit area in the plurality of unit areas and the average pixel value after the smoothing process of each unit area. To each pixel value in the band-shaped region extending parallel to the second diameter direction from each unit region, a difference corresponding to the unit region is added. In this way, in the image based on the corrected actual image data, the average value of the plurality of pixels in each strip-shaped area is equal to or approximately equal to the average pixel value of the predetermined unit area. Therefore, in the image based on the corrected actual image data, it is suppressed that the average color of the plural portions of one surface of the substrate regarded as the first diameter direction is different. As a result, in the visual inspection using the image based on the corrected actual image data, the presence or absence of defects in the surface state of the substrate can be easily and accurately determined.

(12) The smoothing process may also be a smoothing process using the moving median method.

(13) On a surface of the substrate, a film having a periodic pattern in the first diameter direction is formed, and the width used in the smoothing process by the moving median method may be greater than the period of the pattern in the first diameter direction.

(14) It is also possible that each pixel constituting each of the plurality of unit areas includes R pixels, B pixels, and G pixels. The step of smoothing includes smoothing for each pixel type, and the step of adding includes each The pixel type performs calculation processing of a plurality of differences, and performs the addition processing of a plurality of differences for each pixel type.

(15) According to still another aspect of the present invention, the substrate inspection method includes the following steps: photographing one side of the substrate held by the holding portion, and generating actual image data representing an image of one side of the substrate; Each of the plurality of unit areas arranged in the first diameter direction of the substrate on the image of the data, calculates the average value of the plurality of pixels constituting the unit area as the average pixel value, and uses the average pixel value of the plurality of unit areas The first smoothing process of the moving median method; calculate the difference between the average pixel value of each unit area before the first smoothing process and the average pixel value after the first smoothing process as the deviation; The deviation of the second smoothing process using the moving maximum method is calculated, and the plurality of deviations after the second smoothing process are calculated as the maximum value of the plural deviations; the third smoothing using the moving minimum method is performed on the deviations of the plurality of unit areas In the smoothing process, the plurality of deviations after the third smoothing process is calculated as the minimum value of the plurality of deviations; the sum of the average pixel value after the first smoothing process in each unit area and the maximum deviation is calculated as the maximum difference; Calculate the sum of the average pixel value after the first smoothing process of each unit area and the minimum deviation as the minimum difference; determine the range from the minimum difference to the maximum difference corresponding to the predetermined unit area as The reference range; and the correction is made in such a way that the range corresponding to the minimum difference to the maximum difference of each unit area is consistent with the reference range, and so that the second diameter from each unit area is orthogonal to the first diameter direction The pixel values in the band-shaped regions extending in parallel are corrected in a manner suitable for the corrected range.

In this substrate inspection method, actual image data representing an image of one surface of the substrate is generated by photographing one surface of the substrate held by the holding portion. For each of the plurality of unit areas, the average value of the plurality of pixels constituting the unit area is calculated as the average pixel value, and the average pixel value of the plurality of unit areas is subjected to the first smoothing process using the moving median method. In this case, the fluctuation of the local average pixel value is appropriately reduced.

The difference between the average pixel value before the first smoothing process and the average pixel value after the first smoothing process in each unit area is calculated as a deviation. The second smoothing process using the moving maximum method is performed on the deviations of the plurality of unit areas, and the plurality of deviations after the second smoothing process is calculated as the maximum value of the plurality of deviations. In addition, the third smoothing process using the moving minimum method is performed on the deviations of the plurality of unit areas, and the plurality of deviations after the third smoothing process is calculated as the minimum value of the plurality of deviations.

The maximum difference is calculated by adding the average pixel value after the first smoothing process of each unit area to the maximum deviation, and by the average pixel value after the first smoothing process of each unit area and the minimum deviation The values are added to calculate the minimum difference.

The range from the minimum value to the maximum value of the difference corresponding to the predetermined unit area is determined as the reference range. The correction is made so that the range corresponding to the minimum difference to the maximum difference of each unit area coincides with the reference range, and the pixel values in each band-shaped area extending from each unit area in the second diameter direction in parallel The method is suitable for correction after correction. In this way, in the image based on the corrected actual image data, the average value of the plurality of pixels in each strip-shaped area is equal to or approximately equal to the average pixel value of the predetermined unit area. In addition, each pixel value in each band-shaped area is expressed so as to fit within the reference range. Therefore, in the image based on the corrected actual image data, it is suppressed that the average color of the plural portions of one surface of the substrate regarded as the first diameter direction is different. As a result, in the visual inspection using the image based on the corrected actual image data, the presence or absence of defects in the surface state of the substrate can be easily and accurately determined.

(16) On a surface of the substrate, a film having a periodic pattern in the first diameter direction is formed by the first smoothing process using the moving median method, the second smoothing process using the moving maximum method, and the film using the moving minimum method The width used for the third smoothing process may be greater than the period of the pattern in the first diameter direction.

(17) Each pixel constituting each of the plurality of unit areas may include R pixels, B pixels, and G pixels, and the step of performing the first smoothing process includes performing the first smoothing process for each pixel type to calculate the deviation The step includes calculating a plurality of deviations for each pixel type, the step of calculating the maximum deviation includes the calculation processing of a plurality of maximum differences for each pixel type, and the step of calculating the minimum deviation includes each pixel type Perform the calculation process of the plurality of minimum differences, the step of calculating the maximum difference includes the calculation process of the plurality of maximum differences for each pixel type, the step of calculating the minimum difference includes the complex number for each pixel type The calculation process of each difference minimum value, the step of determining the reference range includes the determination process of the reference range for each pixel type, and the correction step includes performing the minimum value of the difference corresponding to each unit area to the difference for each pixel type The correction process in which the range of the maximum value is consistent with the reference range, and the correction process of adapting each pixel value in each band region to the corrected range.

(18) A substrate processing method according to yet another aspect of the present invention includes the steps of: forming a film on one side of the substrate by supplying a processing liquid to one side of the substrate; and using the above-mentioned substrate inspection method to inspect one side The film-forming substrate.

In this substrate processing method, the surface state of one surface of the film-formed substrate is inspected by the above substrate inspection method. Thereby, in the visual inspection using the image representing one side of the substrate, the presence or absence of defects of the film formed on one side of the substrate can be easily and accurately determined. As a result, the occurrence of defective processing of the substrate is reduced. [Effect of invention]

According to the present invention, the user can easily and accurately determine the presence or absence of defects in the visual inspection of the image using the substrate.

Hereinafter, the substrate inspection apparatus, the substrate processing apparatus, the substrate inspection method, and the substrate processing method according to the embodiments of the present invention will be described using drawings. In the following description, the substrate refers to a substrate for FPD (Flat Panel Display), a substrate for an optical disc, a magnetic disk for a semiconductor substrate, a liquid crystal display device, an organic EL (Electro Luminescence) display device, etc. Substrates, substrates for optomagnetic discs, substrates for photomasks, ceramic substrates, substrates for solar cells, etc. In addition, the substrate used as the inspection target in this embodiment has one side (main surface) and the other side (back surface), and a film having a periodic pattern in two directions orthogonal to each other is formed on one surface. The pattern period in each direction is determined according to the size (grain size) of the exposure device that can expose the substrate in one shot. Examples of the film formed on one surface of the substrate include a resist film, an anti-reflection film, and a resist cover film.

[1] The first embodiment

(1) Structure of the substrate inspection apparatus FIG. 1 is an external perspective view of the substrate inspection apparatus of the first embodiment, FIG. 2 is a schematic side view showing the internal structure of the substrate inspection apparatus 200 of FIG. 1, and FIG. 3 is a diagram of FIG. 1. A schematic plan view of the internal structure of the substrate inspection device 200. As shown in FIG. 1, the substrate inspection device 200 has a frame portion 210. The frame portion 210 includes a rectangular bottom surface portion 211 and four rectangular side portions 212 to 215. The side portions 212 and 214 are located at both ends of the bottom portion 211 in the longitudinal direction, and the side portions 213 and 215 are located at both ends of the bottom portion 211 in the short direction (width direction). The frame portion 210 has a substantially rectangular upper opening. The frame portion 210 may further include an upper surface portion that closes the upper opening.

Hereinafter, the short side direction of the bottom surface portion 211 is referred to as a left-right direction, and the longitudinal direction of the bottom surface portion 211 is referred to as a front-back direction. In the left-right direction, the direction from the side surface portion 215 toward the side surface portion 213 is defined as the right side, and the direction opposite thereto is defined as the left side. Furthermore, in the front-rear direction, the direction from the side portion 214 toward the side portion 212 is defined as the front, and the opposite direction is defined as the rear. A slit-shaped opening 216 for transferring the substrate W between the outside and inside of the frame body 210 is formed in the portion from the side portion 212 to the front portion of the side portion 213.

In the frame body portion 210, a light projecting portion 220, a reflecting portion 230, an imaging portion 240, a substrate holding device 250, a moving portion 260, and a cut detection portion 270 are housed.

The light projection unit 220 includes, for example, one or a plurality of light sources, and is mounted on the inner surfaces of the side surfaces 213 and 215 of the frame body 210 so as to extend in the left-right direction. The reflection part 230 includes, for example, a mirror, and is attached to the inner surfaces of the side parts 213 and 215 of the frame part 210 so as to extend behind the light projection part 220 and in the left-right direction.

The imaging unit 240 is attached to the bottom surface 211 of the frame body 210 at a position behind the reflection unit 230. The imaging unit 240 includes imaging elements arranged linearly so that a plurality of pixels extend in the left-right direction, and one or a plurality of condenser lenses. In this example, a color CCD (charge coupled element) line sensor is used as the imaging element. In addition, a color CMOS (Complementary Metal Oxide Film Semiconductor) line sensor can also be used as the imaging element.

The reflecting unit 230 has a reflecting surface that faces diagonally downward and rearward, and is arranged in the field of view of the imaging unit 240. The reflection surface of the reflection part 230 forms an imaging area of the imaging part 240 below the light projection part 220 and the reflection part 230. The imaging area of the imaging unit 240 extends linearly in the left-right direction.

As will be described later, the substrate W to be inspected is carried into the frame portion 210 from the opening 216, and the carried substrate W passes under the light projection 220. The light projecting section 220 emits the cross-sectional light extending in the left-right direction longer than the diameter of the substrate W obliquely downward and rearward. As shown in FIG. 2, part of the light emitted obliquely downward and rearward from the light projecting section 220 is reflected obliquely upward and rearward by a surface (upper surface) of the substrate W in the imaging area of the imaging section 240, and is reflected by the reflective section 230 It is reflected from the rear and received by the imaging unit 240.

The substrate holding device 250 is, for example, a spin chuck, and includes a driving device 251 and a spin holding part 252. The driving device 251 is, for example, an electric motor, and has a rotating shaft 251a. The driving device 251 is provided with an encoder (not shown). The rotation holding portion 252 is attached to the front end of the rotation shaft 251a of the driving device 251, and is driven to rotate around the vertical axis while maintaining the substrate W to be inspected.

As shown in FIG. 3, the moving part 260 includes a plurality of (two in this example) guide members 261 and a moving holding part 262. The plurality of guide members 261 are attached to the bottom surface portion 211 of the frame body portion 210 so as to be aligned in the left-right direction and extend in the front-rear direction. The movement holding portion 262 is configured to hold the substrate holding device 250 while being movable along the plurality of guide members 261 in the front-rear direction. With the substrate holding device 250 holding the substrate W, the movement holding portion 262 is moved in the front-rear direction, and the substrate W is passed under the light projection portion 220.

The cut detection unit 270 is, for example, a reflective photoelectric sensor including a light-emitting element and a light-receiving element, and is attached to the upper portion in front of the inner surface of the side portion 215 of the frame body 210. When the peripheral portion of the substrate W to be inspected is located below the cut detection unit 270, the cut detection unit 270 emits light downward and receives the reflected light from the substrate W. Here, when a cut is formed in the portion of the substrate W located below the cut detection unit 270, the amount of light received by the cut detection unit 270 decreases. The cut detection unit 270 detects the presence or absence of a cut on the substrate W based on the received light amount of the reflected light from the substrate W rotated by the substrate holding device 250. In addition, a transmission type photoelectric sensor may be used as the cut detection unit 270.

As shown in FIG. 1, a control device 400 and a display unit 280 are provided outside the housing 210. The control device 400 controls the light projection unit 220, the imaging unit 240, the substrate holding device 250, the moving unit 260, the cut detection unit 270, and the display unit 280. The display unit 280 displays an automatic determination result of the presence or absence of a defect of the substrate W to be inspected, and an image of the substrate W for visual inspection. The details of the control device 400 will be described later. In addition, in FIGS. 2 and 3, illustration of the control device 400 and the display unit 280 is omitted.

In the substrate inspection apparatus 200 described above, when inspecting the substrate W to be inspected, the entire surface of the substrate W is imaged. The operation at the time of imaging will be described. In the initial state, as shown in FIG. 1, the substrate holding device 250 is located in the front part inside the frame part 210. In this state, the substrate W to be imaged is carried into the frame portion 210 through the opening 216 and held by the substrate holding device 250.

Next, the substrate W is rotated once by the substrate holding device 250, and the light is emitted to the peripheral portion of the substrate W by the cut detection unit 270, and the reflected light is received by the cut detection unit 270. With this, the cut of the substrate W is detected, and the orientation of the substrate W is determined. Thereafter, the substrate W is rotated by the substrate holding device 250 so that the substrate W faces a specific direction.

Next, in a state where light is emitted from the light projecting section 220, the substrate W is moved backward by the moving section 260. At this time, the entire surface of the substrate W is irradiated with cross-sectional light extending in the left-right direction by the substrate W passing under the light projecting portion 220. As described above, in the imaging area of the imaging unit 240, the light reflected from the substrate W is further reflected by the reflecting unit 230 and guided to the imaging unit 240. The imaging element of the imaging unit 240 receives the light reflected from one surface of the substrate W at a specific sampling period, and sequentially photographs a plurality of parts in the front-back direction on one surface of the substrate W. Each pixel constituting the imaging element outputs pixel data indicating a value corresponding to the amount of received light. With this, based on the plurality of pixel data output from the imaging section 240, image data representing the entire image on one surface of the substrate W is generated.

Thereafter, the light output of the light projecting section 220 is stopped, and the substrate is moved from a position rearward of the reflecting section 230 to a position forward of the light projecting section 220 by the moving section 260. Finally, the substrate W is carried out through the opening 216 to the outside of the frame 210.

(2) An image based on image data generated by imaging FIG. 4(a) is a diagram showing an example of an actual image showing one side of a substrate, and FIG. 4(b) is a diagram showing the use of the substrate inspection apparatus 200 of FIG. , Based on an example of the previous image of the image data generated by photographing the substrate W of FIG. 4(a). On one surface of the substrate W shown in FIG. 4(a), there is no defect. In addition, in Figs. 4(a) and (b), the illustration of the cut is omitted.

In the image of FIG. 4(a), the average color of the plural portions on one surface of the substrate W is uniform. With this, the periodic pattern of the film formed on one surface of the substrate W can be clearly viewed. On the other hand, in the image of FIG. 4(b), as shown by hatching, the two ends of the substrate W and the vicinity thereof are represented by colors different from the central portion including the center of the substrate W. The reason will be explained.

Each pixel of the imaging element provided in the imaging unit 240 is composed of an R pixel that receives red light, a G pixel that receives green light, and a B pixel that receives blue light. The refractive index of light of the film formed on the substrate W varies with wavelength. In addition, the transmittance and reflectance of light of the film on the substrate W may also vary with wavelength. Therefore, if it is reflected on one surface of the substrate W and the incident angle of light incident on the imaging surface of the imaging element of the imaging unit 240 is different, the ratio of the received light amounts of the R pixel, G pixel, and B pixel is different. As a result, the ratio of the R pixel value, the G pixel value, and the B pixel value of the image data is different due to the angle of incidence of light on the imaging surface of the imaging unit 240. The color of an image is determined by the combination of hue, lightness, and saturation. As described above, when the ratio of the R pixel value, the G pixel value, and the B pixel value is different, the hue will be different. Furthermore, even when the above ratios are equal, when the R pixel value, the G pixel value, and the B pixel value are different, the brightness is also different. From these results, it can be seen that if the incident angle of light to the imaging surface of the imaging unit 240 is different, the color of the image represented by the image data is different.

FIG. 5 is a schematic plan view showing the state in which the entire surface of one surface of the substrate W is imaged by the imaging unit 240 in the substrate inspection apparatus 200 of FIG. 1. As shown in FIG. 5, a first virtual surface VS1 extending in the front-rear direction and perpendicular to one surface of the substrate W is defined by the center WC of the substrate W held by the substrate holding device 250. In addition, behind the light projecting section 220 and the reflecting section 230, a second virtual plane VS2 orthogonal to the front-rear direction is defined. Furthermore, a virtual point VP is defined on the intersection of the first virtual surface VS1 and the second virtual surface VS2.

The imaging surface 242 of the imaging unit 240 is disposed on the second virtual surface VS2, and the center of the imaging surface 242 is disposed at the virtual point VP. In this case, the incident angle γ of light incident on the imaging surface 242 of the imaging unit 240 from one end WE1 and the other end WE2 of the substrate W in the left-right direction can be made equal. However, if the distance between the reflecting portion 230 and the imaging portion 242 is short, the incident angle γ of light incident on the imaging surface 242 of the imaging portion 240 from one end WE1 and the other end WE2 of the substrate W and the light from the substrate W The difference of the incident angle 0 at which the center WC enters the imaging surface 242 of the imaging unit 240 increases. In the substrate inspection apparatus 200, in order to suppress the enlargement of the front-back direction of the frame portion 210, it is difficult to increase the distance between the reflection portion 230 and the front-back direction of the imaging surface 242. Therefore, the color of the image of one end WE1 and the other end WE2 of the substrate W is greatly different from the color of the image of the center portion of the substrate W including the center WC of the substrate W.

As described above, if on the image based on the image data, both ends and the vicinity of the substrate W are expressed in a different color from the central portion of the substrate W, then the visual inspection of the substrate W using the image, in It is difficult to judge defects on the image. Therefore, in the substrate inspection apparatus 200, the image data generated by imaging is corrected in such a manner that the average colors of a plurality of parts on one surface of the substrate W are equal or approximately equal, and display image data for visual inspection is generated.

(3) Method for generating data for image display in the first embodiment FIG. 6 to FIG. 18 are diagrams for explaining the method for generating data for image display in the first embodiment. In the following description, the image data generated by photographing the substrate W in the substrate inspection device 200 is referred to as actual image data. The actual image data includes the value representing the light receiving amount of the R pixel, the value representing the light receiving amount of the G pixel, and the value representing the light receiving amount of the B pixel as information for each pixel. In addition, in the image of the substrate W based on the actual image data, one of the diameter directions of the substrate W is called the X direction, and the other diameter direction of the substrate W orthogonal to the X direction is called the Y direction. The X direction corresponds to the left-right direction of the substrate inspection apparatus 200 of FIG. 1, and the Y direction corresponds to the front-back direction of the substrate inspection apparatus 200 of FIG. 1.

First, as shown in FIG. 6, in an image based on actual image data, a plurality of unit areas UA arranged in the X direction are set at the central portion of the substrate W in the Y direction. Each unit area UA includes a plurality of pixels PI, has a width of 1 pixel in the X direction, and has a length of 100 pixels in the Y direction. With this, each unit area UA corresponds to each pixel position in the X direction. In addition, the length of the unit area UA in the Y direction may be longer than the width in the X direction and smaller than the diameter of the substrate W.

Next, the average value of the R pixels, the average value of the G pixels, and the average value of the B pixels of the plurality of pixels PI in each unit area UA are calculated. The average value of R pixels, the average value of G pixels, and the average value of B pixels calculated for each unit area UA are set to the average pixel value of R pixels, the average pixel value of G pixels, and B corresponding to the unit area UA, respectively The average pixel value of the pixel. The color obtained based on the ratio of the average pixel values of RGB and the magnitude of these values becomes the average color representing the colors of the plurality of pixels PI in each unit area UA. In addition, the central value of the R pixels, the central value of the G pixels, and the central value of the B pixels of the plurality of pixels PI in each unit area UA can be respectively set as the average pixel value of the R pixel and the average pixel value of the G pixel And the average pixel value of B pixels.

FIG. 7 shows an example of the average pixel value of RGB calculated from actual image data by a graph. In FIG. 7, the vertical axis represents the pixel value, and the horizontal axis represents the pixel position in the X direction on the image of the substrate W. Also, one end (left end) of the horizontal axis represents the pixel position of one end (left end) in the X direction on the image of the substrate W, and the other end (right end) of the horizontal axis represents the image of the substrate W The pixel position at the other end (right end) in the X direction. In addition, in FIG. 7, the line connecting the average pixel value of the R pixel from one end in the X direction to the other end is represented by a one-point chain line (hereinafter referred to as the R average pixel value line RR), from one end in the X direction The line connecting the average pixel value of the G pixel to the other end is represented by a dotted line (hereinafter referred to as the G average pixel value line RG), and the line connecting the average pixel value of the B pixel from one end in the X direction to the other end It is represented by a solid line (hereinafter referred to as B average pixel value line RB). According to the graph of FIG. 7, the ratio of the average pixel value of RGB in the central portion of the substrate W is different from the ratio of the average pixel value of RGB in the both ends of the substrate W and its vicinity.

Next, in order to obtain the period in the X direction of the pattern of the film formed on one surface of the substrate W, for each of the R average pixel value line RR, the G average pixel value line RG, and the B average pixel value line RB, sequentially calculate The data including k (k is a natural number of 2 or more) average pixel values of a part of the area (hereinafter referred to as the central area) of the center of the substrate W continuously arranged in the X direction are offset from the central area of the pixel by pixel in the X direction Correlation coefficient of the data of k average pixel values continuously arranged in the X direction. In this embodiment, k is set to about 200.

FIG. 8 is a graph showing an example of correlation coefficients calculated from the R average pixel value line RR, the G average pixel value line RG, and the B average pixel value line RB of FIG. 7. In FIG. 8, the vertical axis represents the correlation coefficient, and the horizontal axis represents the pixel position in the X direction on the image of the substrate W. In addition, in FIG. 8, the correlation coefficient corresponding to the R average pixel value line RR is represented by a dotted line, and the correlation coefficient corresponding to the G average pixel value line RG is represented by a dotted line, corresponding to the B average pixel value line RB The correlation coefficient is represented by a solid line.

Next, from the three correlations calculated for the R average pixel value line RR, the G average pixel value line RG, and the B average pixel value line RB, respectively, select a correlation coefficient that represents a significant periodicity in the direction of the pixel position. In the example of FIG. 8, the correlation coefficient corresponding to the B average pixel value line RB is selected. In the waveform of the selected correlation coefficient, as shown by the hollow arrow in FIG. 8, a peak exceeding the predetermined threshold th0 and corresponding to the central region of the substrate W is identified as the central peak.

Next, as indicated by the thick solid arrows in FIG. 8, for the central peak, any one of the two peaks that exceeds the predetermined threshold th0 and is adjacent to the central peak is extracted. Furthermore, the distance (number of pixels) in the X direction between the central peak and the captured peak is calculated. The distance calculated in this way is a period in the X direction of the pattern of the film formed on one surface of the substrate W (hereinafter referred to as a pattern period).

Next, the average pixel value of RGB shown in FIG. 7 is smoothed by the moving median method. Specifically, for each unit area UA, one of the unit areas UA (left side) is calculated with a pattern period and the other of the unit area UA (right side) is calculated with a width of 1 pattern period. . In this way, the center value of the movement in the X direction is calculated by adding a width of "1" to the double value of the pattern period. In this way, the fluctuation of the average pixel value caused by the pattern of the film is appropriately reduced.

In FIG. 9, the first R reference curve R1 smoothed by the R average pixel value line RR of FIG. 7 is represented by a dotted line, and the first R reference curve smoothed by the G average pixel value line RG of FIG. 7 The G reference curve G1 is represented by a dotted line, and the first B reference curve B1 smoothed by the B average pixel value line RB of FIG. 7 is represented by a solid line.

There is a case where no film is formed on one surface of the substrate W at the outer peripheral end and its vicinity. Alternatively, when the film is formed at the outer peripheral end and its vicinity, the pattern of the film formed at the outer peripheral end and its vicinity also has a different periodicity from the pattern of the film formed at the central portion of the substrate W. Therefore, as shown by the thick two-dot chain line in FIG. 9, although the first R reference curve R1, the first G reference curve G1, and the first B reference curve B1 are smoothed, they are still at both ends in the X direction Significantly disordered.

Therefore, it is estimated that the average pixel value at one end should be calculated assuming that one end on the image of the substrate W is not disturbed. Specifically, the ideal average pixel value of one pattern period of one end on the image including the substrate W is estimated from the average pixel value of another pattern period adjacent to the part.

FIG. 10(a) shows the first R reference curve R1, the first G reference curve G1, and the first B reference curve B1 that are away from an end in the X direction by about two pattern periods. Here, the pixel position farther from the one end part by 2 pattern periods is set to p ₀ , and the pixel position farther from the pixel position p ₀ to the one end part by any distance less than 1 pattern period is set to p _n . Further, since the end portion remote from the position of the pixel pattern period of 1 to p _'0, since the pixel position p' away from the pixel position of any pattern is less than the distance set period p _'n-0 to the end portion. The distance between the pixel position of the pixel position p ₀ p _'0, p' _n, equal to the distance between the p _n.

In this case, for the first R reference curve R1, the pixel value of the pixel position p ₀ is set to R ₀ , the pixel value of the pixel position p _n is set to R _n , and the pixel value of the pixel position p′ ₀ is set to R 'when the case of _0, the pixel position p' _n of the pixel value over the R _'n-can be estimated based on the formula (1). _R'n = (R _n －R ₀ )+R' ₀ …(1)

Also, for the first G reference curve G1, the pixel value at the pixel position p ₀ is set to G ₀ , the pixel value at the pixel position p _n is set to G _n , and the pixel value at the pixel position p′ ₀ is set to G′ when the case of _0, the pixel location p 'over the value of the pixel _n G' _n can be estimated based on the following equation (2). _{G 'n = (G n -G} 0) + G' 0 ... (2)

Furthermore, for the first B reference curve B1, the pixel value at the pixel position p ₀ is set to B ₀ , the pixel value at the pixel position p _n is set to B _n , and the pixel value at the pixel position p′ ₀ is set to B 'is ₀ case, the pixel position p' over the value B of the pixel _{n 'n} can be estimated based on the formula (3). _B'n = (B _n －B ₀ )+B' ₀ …(3)

Using the above formulas (1), (2), and (3), the average pixel value of one pattern period in one end in the X direction is estimated, and the estimation result is determined as a plurality of unit areas of one pattern period in one end The average pixel value of RGB in UA. Thereby, as shown in FIG. 10(b), the disorder of one end of the first R reference curve R1, the first G reference curve G1, and the first B reference curve B1 is removed.

In addition, the ideal average pixel value for one pattern period on the other end of the image including the substrate W is also estimated by the average pixel value for another pattern period adjacent to the portion. FIG. 10(c) shows the first R reference curve R1, the first G reference curve G1, and the first B reference curve B1 that are away from the other end in the X direction by about 2 pattern periods. In this example, the pixel position farther from the other end by 2 pattern periods is set to p ₀ , and the pixel position farther from the pixel position p ₀ to the other end than any pattern period is set to p _n . Further, the other end portion remote from the position of the pixel pattern period of 1 to p _'0, since the pixel position p' away from the pixel position of any pattern is less than the distance set period p _'n-0 to the other end portion. The distance between the pixel position of the pixel position p ₀ p _'0, p' _n, equal to the distance between the p _n.

In this case, the above formulas (1), (2), and (3) are used to estimate the average pixel value of one pattern period in the X direction including the other end, and the estimation result is determined as one pattern period at the other end The RGB average pixel value of a plurality of unit areas UA. As a result, as shown in FIG. 10(d), the disorder of the other ends of the first R reference curve R1, the first G reference curve G1, and the first B reference curve B1 is removed. FIG. 11 shows the correction of the total of the first R reference curve R1, the first G reference curve G1, and the first B reference curve B1 at both ends based on the estimation result.

Next, for the average pixel value represented by the R average pixel value line RR, the G average pixel value line RG, and the B average pixel value line RB in FIG. 7, it is estimated that it should be calculated assuming that one end on the image of the substrate W is not disturbed The average pixel value at both ends is corrected based on the estimation result. Here, in order to more accurately determine the range of pixel positions where the pattern of the film is disturbed (hereinafter referred to as a useless range), the following processing is performed.

First, for each unit area UA, the difference between the average pixel value before smoothing indicated by the R average pixel value line RR in FIG. 7 and the average pixel value after smoothing indicated by the first R reference curve R1 in FIG. 11 is calculated The absolute value is used as the deviation evaluation value of R pixels. Also, for each unit area UA, the average pixel value before smoothing indicated by the G average pixel value line RG in FIG. 7 and the average pixel value after smoothing indicated by the first G reference curve G1 in FIG. 11 are calculated. The absolute value of the difference is used as the deviation evaluation value of G pixels. Furthermore, for each unit area UA, the average pixel value before smoothing indicated by the B average pixel value line RB in FIG. 7 and the average pixel value after smoothing indicated by the first B reference curve B1 in FIG. 11 are calculated The absolute value of the difference is taken as the evaluation value of the deviation of B pixels. FIG. 12 shows the evaluation value of the deviation of B pixels. In addition, the deviation evaluation value of the R pixel and the G pixel is calculated so as to substantially overlap the deviation evaluation value of the B pixel, for example.

Next, for the average pixel value before smoothing represented by the R average pixel value line RR of FIG. 7, the absolute difference between the average pixel values of the two unit areas UA adjacent to each unit area UA and the unit area UA is calculated. Value as the difference evaluation value of R pixels. In addition, for the average pixel value before smoothing represented by the G average pixel value line RG in FIG. 7, the absolute difference between the average pixel values of the two unit areas UA adjacent to each unit area UA and the unit area UA is calculated. Value as the difference evaluation value of G pixels. Furthermore, for the average pixel value before smoothing indicated by the B average pixel value line RB in FIG. 7, the difference between the average pixel values of the two unit areas UA adjacent to each unit area UA and the unit area UA is calculated The absolute value is used as the difference evaluation value of B pixels. Fig. 13 shows the evaluation value of the difference of B pixels. In addition, the difference evaluation value of the R pixel and the G pixel is calculated, for example, so as to substantially overlap with the difference evaluation value of the B pixel.

Thereafter, based on the deviation evaluation value and the difference evaluation value of RGB, a useless range including one end portion in the X direction on the image of the substrate W is determined. FIG. 14(a) shows the evaluation value of the deviation of RGB away from an end in the X direction by about 2 pattern periods. In addition, FIG. 14(b) shows the evaluation value of the difference of RGB away from an end in the X direction by about 2 pattern periods. In addition, in FIGS. 14(a) and (b) and FIGS. 14(c) and (d) described later, the evaluation value corresponding to the R pixel is indicated by a dotted line, and the evaluation value corresponding to the G pixel is indicated by a dotted line Indicates that the evaluation value corresponding to the B pixel is indicated by a solid line.

Here, regarding the deviation evaluation value, as shown in FIG. 14(a), the threshold value th1 is predetermined. In addition, as shown in FIG. 14(b), the difference evaluation value is assumed to be a threshold value th2 predetermined. In this state, for each unit area UA (per 1 pixel) from one end in the X direction to the other end, it is determined whether the evaluation value of all deviations of RGB is below the threshold th1 and the evaluation value of all differences of RGB The threshold is below th2. Therefore, first determine the range from the pixel position of the unit area UA to one end when the evaluation values of all deviations of RGB become below the threshold th1 and the evaluation values of all differences of RGB become below the threshold th2, as the useless range UN1 .

Thereafter, based on the deviation evaluation value and the difference evaluation value of RGB, the useless range of the other end portion in the X direction on the image including the substrate W is determined. FIG. 14(c) shows the evaluation value of the deviation of RGB away from the other end in the X direction by about 2 pattern periods. In addition, FIG. 14(d) shows the evaluation value of the difference in RGB away from the other end in the X direction by about 2 pattern periods.

Regarding the other end, also in the same way as the example of the above one end, for each unit area UA (per 1 pixel) from the other end in the X direction to one end, it is determined whether all the deviation evaluation values of RGB are critical If the value is below th1 and all the difference evaluation values of RGB are below the threshold th2. Therefore, first determine the range from the pixel position of the unit area UA to the other end of the unit area UA when all the deviation evaluation values of RGB become below the threshold value th1 and all the difference evaluation values of RGB become below the threshold value th2 UN2.

Thereafter, as shown by hatching in FIG. 15(a), the R average pixel value line RR, the G average pixel value line RG, and the B average pixel value line RB of FIG. 7 are located in FIG. 14(a), (b). The average pixel value shown in the part of the useless range UN1 is corrected. Specifically, as in the example of FIG. 10( a ), based on the average pixel value of RGB of one pattern period adjacent to the unnecessary range UN1, the ideal average pixel value of RGB to be calculated in the unnecessary range UN1 is estimated. Furthermore, the result of the determination is determined as the average pixel value of RGB in the plural unit areas UA located in the useless range UN1. As a result, as shown in FIG. 15(b), the R average pixel value line RR, the G average pixel value line RG, and the B average pixel value line RB are corrected.

Thereafter, as shown by hatching in FIG. 15(c), the R average pixel value line RR, the G average pixel value line RG, and the B average pixel value line RB of FIG. 7 are located in FIGS. 14(c) and (d). The average pixel value shown in the part of the useless range UN2 is corrected. Specifically, as in the example of FIG. 10(c), based on the average pixel value of RGB of one pattern period adjacent to the part of the useless range UN2, the ideal average pixel value of RGB to be calculated in the useless range UN2 is estimated . Furthermore, the estimation result is determined as the average pixel value of RGB in the plural unit areas UA located in the useless range UN2. Thereby, as shown in FIG. 15(d), the R average pixel value line RR, the G average pixel value line RG, and the B average pixel value line RB are corrected. FIG. 16 shows the R average pixel value line RR, the G average pixel value line RG, and the B average pixel value line RB corrected at both ends based on the estimation result.

Next, for the average pixel value of RGB shown in each of the R average pixel value line RR, the G average pixel value line RG, and the B average pixel value line RB of FIG. 16 modified from both ends, as in the example of FIG. 9 Similarly, smoothing processing using the moving median method is performed. In this way, the fluctuation of the average pixel value caused by the pattern of the film is appropriately reduced. In addition, here, instead of the moving median method, smoothing processing using the moving average method may be performed.

In FIG. 17, the second R reference curve R2 smoothed by the R average pixel value line RR of FIG. 16 is represented by a dotted line, and the second R reference curve smoothed by the G average pixel value line RG of FIG. 16 The G reference curve G2 is represented by a dotted line, and the second B reference curve B2 smoothed by the average pixel value line RB of FIG. 16 is represented by a solid line.

Here, as shown by the thick solid line in FIG. 18, each unit area UA corresponding to each pixel position in the X direction is defined on a band-shaped area BA extending in the Y direction on the image of the substrate W.

Next, a correction process that matches all the average pixel values shown in the second R reference curve R2 in the X direction with the specific reference value is applied to all R pixel values of the actual image data. In this example, the average pixel value of the unit area UA located at the center of the substrate W among the average pixel values of the R pixels shown by the second R reference curve R2 is set as the reference value Rv. Further, for each unit area, the difference between the reference value Rv and the average pixel value indicated by the second R reference curve R2 is calculated. Furthermore, the difference between the R pixel value of each pixel in the band-shaped area BA extending from each unit area UA in the Y direction is added to the unit area UA. Regarding this correction process, using the plane coordinate system defined by the axes in the X direction and the Y direction, the R pixel value of any pixel on the image of the substrate W is denoted as R _{(x, y)} , which corresponds to the X of the pixel When the average pixel value on the second R reference curve R2 of the pixel position in the direction is recorded as R _x , the corrected R pixel value R′ _{(x, y)} can be expressed by the following formula (4). R' _(x,y) = R _(x,y) -R _x + Rv…(4)

In addition, for all the G pixel values of the actual image data, the same correction process as that for the R pixel value described above is also performed. In this example, the average pixel value of the unit area UA located at the center of the substrate W among the average pixel values of the G pixels shown by the second G reference curve G2 is set as the reference value Gv. Regarding this correction process, the G pixel value of any pixel on the image of the substrate W is denoted as G _{(x, y)} , and the average value on the second G reference curve G2 corresponding to the pixel position in the X direction of the pixel When the pixel value is written as G _x , the corrected G pixel value G′ _{(x, y)} can be expressed by the following formula (5). G' _(x,y) = G _(x,y) -G _x +Gv…(5)

Furthermore, for all the B pixel values of the actual image data, the same correction process as that for the above R pixel value is also performed. In this example, the average pixel value of the unit area UA located at the center of the substrate W among the average pixel values of the B pixels shown by the second B reference curve B2 is set as the reference value B _v . Regarding this correction process, the B pixel value of any pixel on the image of the substrate W is denoted as B _{(x, y)} , and the average on the second B reference curve B2 corresponding to the pixel position in the X direction of the pixel When the pixel value is recorded as B _x , the corrected B pixel value B′ _{(x, y)} can be expressed by the following formula (6). B' _(x,y) = B _(x,y) -B _x +B _v …(6)

By using the above formulas (4), (5), (6) to correct all pixels of the actual image data, display image data is generated. As a result, in the image represented by the image data for display, the average colors of the plurality of band-shaped areas BA on one surface of the substrate W in the left-right direction are equal or approximately equal.

(4) Control system of substrate inspection apparatus 200 FIG. 19 is a block diagram showing a control system of the substrate inspection apparatus 200 of the first embodiment. The control device 400 is composed of a CPU (Central Processing Unit), RAM (Random Access Memory) and ROM (Read Only Memory). As shown in FIG. 19, it has a control unit 401, an image generation unit 402, and The unit 403, the image determination memory unit 404, and the display image data generation unit 405. In the control device 400, the CPU executes a computer program stored in a ROM or other storage medium to realize the above-mentioned functional units. In addition, some or all of the functional components of the control device 400 can also be implemented by hardware such as electronic circuits.

Regarding the substrate holding device 250 and the cut detection unit 270, the control unit 401 obtains an output signal from the encoder of the driving device 251 (FIG. 2) of the substrate holding device 250, detects the rotation angle of the driving device 251 (the rotation angle of the substrate W), And the result of the cut detection by the cut detection unit 270 is obtained. The control unit 401 determines the direction of the substrate W based on the rotation angle of the drive device 251 when the cut is detected, and controls the operation of the substrate holding device 250 based on the determination result.

Regarding the light projecting unit 220, the moving unit 260, and the imaging unit 240, the control unit 401 controls the light projecting unit 220, the moving unit 260, and the imaging unit 240 so as to capture the entire surface of the substrate W held on the substrate holding device 250.

The image generation unit 402 generates image data representing the entire image on one surface of the substrate W based on the plurality of pixel data output from the imaging unit 240. The determination unit 403 automatically determines whether or not there is a defect in the surface state on one surface of the substrate W based on the image data generated in the image generation unit 402. The image determination memory unit 404 memorizes the automatic determination result of the presence or absence of a defect in the use determination unit 403.

The display image data generating unit 405 sets the image data generated in the image generating unit 402 as the above-mentioned actual image data, and generates display image data indicating the image to be displayed on the display unit 280 based on the actual image data .

More specifically, the display image data generation unit 405 includes a smoothing unit 411 and a correction unit 412. The smoothing unit 411 calculates the average pixel value of the plurality of pixels constituting the unit area UA for each of the plurality of unit areas UA (FIG. 6) arranged in the X direction on the image based on the actual image data. Moreover, the smoothing unit 411 smoothes the average pixel value of the plurality of unit areas UA.

In addition, the smoothing unit 411 may also estimate the ideal average pixel value to be calculated for each of the plurality of unit regions UA located at both ends of the substrate W by calculating the average pixel value for the other plurality of unit regions UA Based on the estimation result, the average pixel value of the plurality of unit areas UA located at both ends of the substrate W is determined.

The correction unit 412 calculates the difference between the smoothed average pixel value of the unit area UA located at the center of the substrate W and the smoothed average pixel value of each unit area UA. Furthermore, the correction unit 412 corrects the actual image data by adding each pixel value in the band-shaped area BA (FIG. 18) extending from each unit area UA in the Y direction to the difference corresponding to the unit area UA. By this, image data for display is generated.

The image determination storage unit 404 further stores the display image data generated by the display image data generation unit 405. The image is displayed on the display unit 280 based on the automatic determination result stored in the image determination memory unit 404 and the image data for display.

(5) Defect determination process As described above, in the substrate inspection device 200, the control device 400 of FIG. 1 automatically determines the presence or absence of defects on the surface state of one surface of the substrate W, and displays the information indicating the substrate W to the user for visual inspection An image of one side. This series of processing is called defect determination processing. FIG. 20 is a flowchart of the defect determination process in the first embodiment. Here, the substrate W to be inspected is referred to as an inspection substrate W.

Before starting the defect determination process, an inspection is performed with high accuracy in advance, and a substrate determined to be defect-free during the inspection is prepared as a sample substrate. The control unit 401 and the image generation unit 402 of FIG. 19 first generate image data representing one surface of the sample substrate by photographing the sample substrate without defects (step S11).

Next, the control unit 401 and the image generation unit 402 generate image data representing one surface of the inspection substrate W by imaging the inspection substrate W (step S12). Furthermore, the determination unit 403 of FIG. 19 automatically determines whether or not there is a defect in the surface state of the inspection substrate W based on the image data of the sample substrate and the image data of the inspection substrate W (step S13). The image determination memory unit 404 of FIG. 19 stores the automatic determination result (step S14).

Next, the smoothing unit 411 of FIG. 19 sets the image data generated in the process of step S12 as actual image data, for a plurality of unit areas UA (FIG. 6) Each of them calculates the average pixel value of the plurality of pixels constituting the unit area UA (step S15). Further, the smoothing unit 411 smoothes the average pixel value of the plurality of unit areas UA (step S16).

Next, the correction unit 412 of FIG. 19 calculates the difference between the smoothed average pixel value of the unit area UA located at the center of the inspection substrate W and the smoothed average pixel value of each unit area UA (step S17). Further, the correction unit 412 adds the difference corresponding to the unit area UA to each pixel value in the strip area BA (FIG. 18) extending from each unit area UA (step S18). By this, image data for display is generated. The image determination storage unit 404 stores the display image data (step S19).

Thereafter, the image determination storage unit 404 causes the image based on the automatic determination result and the display image data to be displayed on the display unit 280 in FIG. 19 (step S20). In this state, the user can perform a visual inspection of one side of the inspection substrate W by viewing the image of the inspection substrate W displayed on the display unit 280.

In the above defect determination processing, the processing of steps S13 and S14 may be performed after the processing of steps S15 to S19, or may be performed simultaneously with the processing of steps S15 to S19.

The inspection substrate W determined to be defective in the process of step S13, or the inspection substrate W determined to be defective by the visual inspection by the user in the process of step S20 becomes an object of precision inspection or regeneration processing.

(6) Effect of the first embodiment (a) In the substrate inspection apparatus 200 of the first embodiment, by imaging one side of the substrate W, actual image data representing an image of one side of the substrate W is generated. For each of the plurality of unit areas UA set on the image based on the actual image data, the average value of the plurality of pixels constituting the unit area UA is calculated as the average pixel value, and the average pixel value of the plurality of unit areas UA Perform smoothing.

The difference between the smoothed average pixel value of the unit area UA located at the center of the substrate W and the smoothed average pixel value of each unit area UA is calculated. A difference corresponding to the unit area UA is added to each pixel value in the strip-shaped area BA extending parallel to the Y direction from each unit area UA. As a result, in the image based on the image data for display, the average value of the plurality of pixels in each band-shaped area BA is equal to or approximately equal to the average pixel value of the unit area UA located at the center of the substrate W. Therefore, in the image based on the image data for display, the average color of the plural portions of one surface of the substrate W that is regarded as the X direction is suppressed. As a result, in the visual inspection using the image based on the image data for display, the presence or absence of defects in the surface state of the substrate W can be easily and accurately determined.

(b) In this embodiment, the average pixel value calculated for each unit area UA is smoothed by the moving median method. In addition, the actual image data is corrected based on the smoothed average pixel value to generate image data for display. In this case, by using the smoothing process of the moving median method, the fluctuation of the local average pixel value is appropriately reduced.

(c) In this embodiment, for each type of R pixel, G pixel, and B pixel constituting one pixel, an average pixel value calculation process, an average pixel value smoothing process, and actual image data correction process are performed . Thereby, it is suppressed that the average hue of the plural portions in the X direction of one surface of the substrate W is regarded as an image based on the image data for display.

(d) In the present embodiment, the ideal average pixel value of the plurality of unit areas UA at both ends of the substrate W located on the image based on the actual image data is based on the complex number at the portions adjacent to the two ends The average pixel value of each unit area UA is estimated. The estimation result is determined as a plurality of average pixel values respectively corresponding to a plurality of unit areas UA located at each end. With this, based on the average pixel value determined for each unit area UA, image data for display is generated. As a result, it is suppressed that the image based on the image data for display shows that the average color of both ends of the substrate W and the average color of the portions adjacent to both ends are significantly different.

(e) In the substrate inspection apparatus 200 of the present embodiment, by the relative movement of the light projecting section 220, the reflecting section 230, the imaging section 240, and the substrate holding device 250, image data representing the entire image of one surface of the substrate W is generated . Therefore, the enlargement of the imaging unit 240 is suppressed.

[2] Second Embodiment The substrate inspection apparatus of the second embodiment has substantially the same configuration as the substrate inspection apparatus 200 of FIG. 1 of the first embodiment. In the substrate inspection apparatus 200 of this embodiment, the method of generating data for image display is different from the method of generating data for image display of the first embodiment.

(1) Method for generating data for image display in the second embodiment FIG. 21 to FIG. 24 are diagrams for explaining the method for generating data for image display in the second embodiment. First, the RGB average represented by the R average pixel value line RR, the G average pixel value line RG, and the B average pixel value line RB of FIG. 16 is calculated in the same order as the method for generating the image display data of the first embodiment. Pixel values.

Furthermore, by performing smoothing processing using the moving median method on the calculated RGB average pixel value, the second R reference curve R2, the second G reference curve G2, and the second B reference curve B2 of FIG. 17 are calculated. Represents the average RGB pixel value after smoothing.

Next, for each unit area UA, the average pixel value before smoothing represented by the R average pixel value line RR in FIG. 16 and the average pixel value after smoothing represented by the second R reference curve R2 in FIG. 17 are calculated. The difference is used as the deviation evaluation value of R pixels. Also, for each unit area UA, the average pixel value before smoothing indicated by the G average pixel value line RG in FIG. 16 and the average pixel value after smoothing indicated by the second G reference curve G2 in FIG. 17 are calculated. The difference is taken as the deviation evaluation value of G pixels. Furthermore, for each unit area UA, the average pixel value before smoothing indicated by the B average pixel value line RB in FIG. 16 and the average pixel value after smoothing indicated by the second B reference curve B2 in FIG. 17 are calculated The difference is used as the deviation evaluation value of B pixels. Fig. 21 shows the calculated deviation evaluation values of the R pixel, G pixel, and B pixel with a dotted chain line, a dotted line, and a solid line, respectively.

Next, for each of the deviation evaluation values of RGB shown in FIG. 21, smoothing processing by the moving maximum method is performed. Specifically, for each unit area UA, one width of the unit area UA (left) is calculated by 1 pattern period, and the other area of the unit area UA (right) is calculated by 1 pattern period. . In this way, the maximum value of the movement in the X direction is calculated by adding the width of "1" to the double value of the pattern period. By this, the fluctuation of the maximum movement value due to the pattern of the film is appropriately reduced. The maximum movement value calculated by this smoothing process is called the maximum deviation.

In addition, for each of the RGB deviation evaluation values shown in FIG. 21, smoothing processing by the moving minimum method is performed. Specifically, for each unit area UA, the minimum movement is calculated with one pattern period on one side (left side) of the unit area UA, and with one pattern period width on the other side (right side) of the unit area UA value. In this way, the minimum value of the movement in the X direction is calculated by adding a width of "1" to the double value of the pattern period. With this, the fluctuation of the moving minimum value due to the pattern of the film is appropriately reduced. The minimum movement value calculated by this smoothing process is called the minimum deviation value.

In FIG. 22, the maximum deviation value and the minimum deviation value corresponding to the R pixel are represented by one-dot chain lines RDmax and RDmin, respectively. In addition, the maximum deviation and the minimum deviation corresponding to the G pixel are indicated by dotted lines GDmax and GDmin, respectively. In addition, the maximum deviation and the minimum deviation corresponding to the B pixel are indicated by solid lines BDmax and BDmin, respectively.

Next, for each of the maximum and minimum deviations of RGB shown in FIG. 22, smoothing processing by the moving average method is performed. Specifically, for each unit area UA, one unit (left) of the unit area UA is calculated with one pattern period, and the other side (right) of the unit area UA is calculated with a width of one pattern period. average value. In this way, the moving average value in the X direction is calculated by adding a width of "1" to the double value of the pattern period.

In FIG. 23, the maximum deviation and the minimum deviation after smoothing corresponding to the R pixels are represented by one-dot chain lines RDmax and RDmin, respectively. In addition, the smoothed maximum deviation and minimum deviation corresponding to the G pixel are indicated by dotted lines GDmax and GDmin, respectively. In addition, the smoothed maximum and minimum deviations corresponding to B pixels are represented by solid lines BDmax and BDmin, respectively.

Next, for each unit area UA, the sum of the average pixel value represented by the second R reference curve R2 in FIG. 17 and the maximum deviation value represented by a dotted line RDmax in FIG. 23 is calculated as the value corresponding to the R pixel. Maximum difference. Further, for each unit area UA, the sum of the average pixel value represented by the second R reference curve R2 in FIG. 17 and the maximum deviation value represented by a dotted line RDmin in FIG. 23 is calculated as the value corresponding to the R pixel. The minimum difference. In addition, for the G pixel and the B pixel, as in the example of the R pixel, for each unit area UA, the maximum difference value and the minimum difference value are calculated.

In FIG. 24, the maximum difference value and the minimum difference value corresponding to the R pixels are represented by one-dot chain lines R3max and R3min, respectively. In addition, the maximum value and minimum value of the difference corresponding to the G pixel are indicated by dotted lines G3max and G3min, respectively. Furthermore, the maximum value and minimum value of the difference corresponding to the B pixel are respectively indicated by solid lines B3max and B3min.

Next, for each of the RGB pixels, a range from the minimum value of the difference calculated to the predetermined unit area UA to the maximum value of the difference is determined as a reference range. In this example, the range from the minimum difference to the maximum difference corresponding to the unit area UA located at the center of the substrate W is determined as the reference range. Furthermore, the correction is made so that the range corresponding to the minimum value of the difference between each unit area UA and the maximum value of the difference coincides with the reference range, and each of the band-shaped areas BA extending from each unit area UA in the Y direction The pixel value is corrected in a manner suitable for the corrected range.

Regarding this correction process, using the plane coordinate system defined by the axes in the X direction and the Y direction, the R pixel value of any pixel on the image of the substrate W is denoted as R _{(x, y)} , which corresponds to the X of the pixel The maximum and minimum value of the difference on the chain line R3max and R3min of one of the dots in Figure 24 in the direction of the pixel position are recorded as maxR _x and minR _x , which will correspond to the difference of the R pixels of the unit area UA located in the center of the substrate W When the maximum value and the minimum value of the difference are respectively recorded as maxRv and minRv, the corrected value R′ _{(x, y)} of the R pixel can be expressed by the following formula (7). R' _(x,y) = {(R _(x,y) －minR _x )÷(maxR _x －minR _x )}×(maxRv－minRv)＋minRv…(7)

Also, the G pixel value of any pixel on the image of the substrate W is denoted as G _{(x, y)} , and the difference between the dotted lines G3max and G3min in FIG. 24 corresponding to the pixel position of the pixel in the X direction is the largest The value and the minimum value of the difference are denoted as maxG _x and minG _x . When the maximum value and the minimum value of the difference of the G pixels corresponding to the unit area UA located in the center of the substrate W are respectively recorded as maxGv and minGv, after correction The value G' _{(x, y)} of the G pixel can be expressed by the following formula (8). G' _(x,y) = {(G _(x,y) －minG _x )÷(maxG _x －minG _x )}×(maxGv－minGv)＋minGv…(8)

Furthermore, the B pixel value of any pixel on the image of the substrate W is denoted as B _{(x, y)} , and the difference between the solid lines B3max and B3min of FIG. 24 corresponding to the pixel position in the X direction of the pixel in FIG. 24 The maximum value and the minimum value of the difference are recorded as maxB _x and minB _x . When the maximum value and the minimum value of the difference corresponding to the B pixel of the unit area UA located in the center of the substrate W are respectively recorded as maxBv and minBv, the correction The value B' _{(x, y) of the} following B pixel can be expressed by the following formula (9). B' _(x,y) = {(B _(x,y) －minB _x )÷(maxB _x －minB _x )}×(maxBv－minBv)＋minBv…(9)

By using the above equations (7), (8), (9) to correct all pixels of the actual image data, image data for display is generated. As a result, in the image represented by the image data for display, the average colors of the plurality of band-shaped areas BA on one surface of the substrate W in the left-right direction are equal or approximately equal.

(2) Control system of substrate inspection apparatus 200 The control system of the substrate inspection apparatus 200 of the second embodiment has the same configuration as the example of FIG. 19 except for the functional configuration of the display image data generating section 405. FIG. 25 is a block diagram showing the functional configuration of the display image data generating section 405 of the second embodiment.

As shown in FIG. 25, the display image data generation unit 405 of the second aspect includes a smoothing unit 421, a deviation calculation unit 422, a deviation maximum value calculation unit 423, a deviation minimum value calculation unit 424, and a difference maximum value calculation unit 425 , The minimum difference calculation unit 426, the reference range determination unit 427, and the correction unit 428.

The smoothing unit 421, like the smoothing unit 411 of FIG. 19 of the first embodiment, calculates for each of a plurality of unit regions UA (FIG. 6) arranged in the X direction on an image based on actual image data The average pixel value of multiple pixels. Further, the smoothing unit 421 performs smoothing processing using the moving median method on the average pixel values of the plurality of unit areas UA.

In addition, the smoothing unit 421 may estimate the ideal average pixel value of the plurality of unit areas UA positioned at both ends of the substrate W, and determine the plurality of plural pixels located at both ends of the substrate W based on the estimation result, similar to the smoothing unit 411 The average pixel value of the unit area UA.

The deviation calculation unit 422 calculates the difference between the average pixel value before smoothing and the average pixel value after smoothing of each unit area UA as a deviation evaluation value. The maximum deviation calculation unit 423 calculates the maximum deviation for each unit area UA by performing a smoothing process using the moving maximum method on the deviation evaluation value of each unit area UA. The deviation minimum value calculation unit 424 calculates the minimum deviation value for each unit area UA by performing a smoothing process using the moving minimum method on the deviation evaluation value of each unit area UA.

In addition, the maximum deviation calculation unit 423 may perform smoothing processing using the moving average method on the maximum deviation calculated for the plurality of unit areas UA. Furthermore, the minimum deviation calculation unit 424 may perform smoothing processing using the moving average method on the minimum deviation calculated for the plurality of unit areas UA.

The difference maximum value calculation unit 425 calculates the sum of the average pixel value smoothed by the moving median method and the maximum deviation value for each unit area UA as the maximum difference value. The difference minimum value calculation unit 426 calculates the sum of the average pixel value smoothed by the moving median method and the minimum deviation value for each unit area UA as the minimum difference value. The reference range determining unit 427 determines the range of the minimum difference to the maximum difference calculated for the unit area UA located at the center of the substrate W as the reference range.

The correction unit 428 corrects the range corresponding to each unit area UA from the minimum difference value to the maximum difference value to match the reference range, and makes the band-shaped area BA extending from each unit area UA in the Y direction (FIG. 18) Each pixel value in the correction is adapted to the corrected range. By this, image data for display is generated.

(3) Defect determination process In the defect determination process of the second embodiment, the process for generating display image data is different from the defect determination process of the first embodiment. Fig. 26 is a flowchart of defect determination processing in the second embodiment. In the following description, one of the series of steps S11 to S14 in the defect determination process of the first embodiment shown in FIG. 20 is called an automatic determination process. In addition, here, the substrate W to be inspected is referred to as an inspection substrate W.

As shown in FIG. 26, when the defect determination process is started, the control unit 401, the image generation unit 402, the determination unit 403, and the image determination storage unit 404 of FIG. 19 perform automatic determination processing (step S20). Next, the smoothing unit 421 of FIG. 25 sets the image data of the inspection substrate W generated in the automatic determination process as actual image data, for a plurality of unit areas arranged in the X direction on the image based on the actual image data Each of UA (FIG. 6) calculates the average pixel value of the plurality of pixels constituting the unit area UA (step S21). Further, the smoothing unit 421 smoothes the average pixel value of the plurality of unit areas UA (step S22).

Next, the deviation calculation unit 422 of FIG. 25 calculates the deviation evaluation value for each unit area UA (step S23). Further, the maximum deviation calculation unit 423 of FIG. 25 calculates the maximum deviation for each unit area UA by performing smoothing processing using the moving maximum method on the calculated deviation evaluation value (step S24). Furthermore, the minimum deviation calculation unit 424 of FIG. 25 calculates the minimum deviation for each unit area UA by performing smoothing processing using the moving minimum method on the calculated deviation evaluation value (step S25).

Thereafter, the difference maximum value calculation unit 425 of FIG. 25 calculates the difference maximum value for each unit area UA by adding the smoothed average pixel value and the deviation maximum value (step S26). Further, the difference minimum value calculation unit 426 of FIG. 25 calculates the minimum difference value by adding the smoothed average pixel value and the minimum deviation value for each unit area UA (step S27).

Next, the reference range determining unit 427 of FIG. 25 determines the range of the minimum difference to the maximum difference calculated for the unit area UA located at the center of the substrate W as the reference range (step S28). Finally, the correction unit 428 of FIG. 25 corrects the range corresponding to each unit area UA from the minimum difference to the maximum difference with the reference range, and extends the band from each unit area UA in the Y direction Each pixel value in the shape area BA (FIG. 18) is corrected in such a way that it fits within the corrected range (step S29). By this, image data for display is generated. The image determination memory unit 404 of FIG. 19 stores the image data for display (step S30).

Thereafter, the image determination memory unit 404 causes the image based on the automatic determination result and the display image data to be displayed on the display unit 280 of FIG. 19 (step S31). In this state, the user can perform a visual inspection of one side of the inspection substrate W by viewing the image of the inspection substrate W displayed on the display unit 280.

In the defect determination process of this embodiment, in the automatic determination process of step S20, the processes of steps S13 and S14 in FIG. 20 may be performed after the processes of steps S21 to S30, or may be performed simultaneously with the processes of steps S21 to S30.

(4) Effects of the second embodiment (a) In the substrate inspection apparatus 200 of the second embodiment, the plurality of unit areas UA of each of the plurality of unit areas UA are the same as the generation order of the display image data of the first embodiment, The average pixel value shown in FIG. 16 is calculated. Furthermore, by performing smoothing processing using the moving median method on the average pixel values of the plurality of unit areas UA, the smoothed average pixel values shown in FIG. 17 are calculated. At this time, by performing smoothing processing using the moving median method, the fluctuation of the local average pixel value is appropriately reduced.

Thereafter, the difference between the average pixel value before smoothing of each unit area UA and the average pixel value after smoothing is calculated as the deviation evaluation value. The deviation evaluation value of the plurality of unit areas UA is smoothed by the moving maximum method, and the plurality of deviation evaluation values after smoothing are calculated as the maximum value of the plurality of deviations. In addition, the deviation evaluation value of the plurality of unit areas UA is subjected to smoothing processing using the moving minimum method, and the smoothed plurality of deviation evaluation values are calculated as the minimum value of the plurality of deviations.

For each unit area UA, the maximum difference value is calculated by adding the average pixel value smoothed by the moving median method to the maximum deviation value. In addition, for each unit area UA, the minimum value of the difference is calculated by adding the average pixel value smoothed by the moving median method to the minimum deviation value.

The range of the minimum difference to the maximum difference corresponding to the unit area UA located at the center of the substrate W is determined as the reference range. The correction is made in such a way that the range corresponding to the minimum difference to the maximum difference of each unit area UA is consistent with the reference range, and that each pixel value in each strip area BA extending from each unit area UA in the Y direction The method is suitable for correction after correction. As a result, in the image based on the image data for display, the average value of the plurality of pixels in each band-shaped area BA is equal to or approximately equal to the average pixel value of the unit area UA located at the center of the substrate W. In addition, each pixel value in each band-shaped area BA is expressed so as to fit within the reference range. Therefore, in the image based on the image data for display, the average color of the plural portions of one surface of the substrate W that is regarded as the X direction is suppressed. As a result, in the visual inspection using the image based on the image data for display, the presence or absence of defects in the surface state of the substrate W can be easily and accurately determined.

(b) In this embodiment, for each type of R pixel, G pixel, and B pixel constituting one pixel, an average pixel value calculation process, an average pixel value smoothing process, and a deviation evaluation value calculation process are performed, Calculation of maximum difference, calculation of minimum difference, calculation of maximum difference, calculation of minimum difference, determination of reference range, and correction of actual image data. As a result, on the image based on the image data for display, the average hue of a plurality of portions in the X direction that is regarded as one surface of the substrate W is suppressed.

[3] Third Embodiment The substrate processing apparatus of the third embodiment includes the substrate inspection apparatus 200 of the first or second embodiment. FIG. 27 is a schematic block diagram showing the overall configuration of the substrate processing apparatus according to the third embodiment. As shown in FIG. 27, the substrate processing apparatus 100 is provided adjacent to the exposure apparatus 500, and includes the substrate inspection apparatus 200 of the first or second embodiment, and includes a control apparatus 110, a transport apparatus 120, a coating apparatus 130, and a development processing section 140 And heat treatment section 150.

The control device 110 includes, for example, a CPU, a memory, or a microcomputer, and controls operations of the transport device 120, the coating processing unit 130, the development processing unit 140, and the heat treatment unit 150. Furthermore, the control device 110 gives a command for inspecting the surface state of one surface of the substrate W to the control device 400 of the substrate inspection device 200 (FIG. 1 ).

The transport device 120 transports the substrate W between the coating processing unit 130, the development processing unit 140, the heat treatment unit 150, the substrate inspection device 200, and the exposure device 500.

The coating processing unit 130 includes a plurality of processing units PU. The processing unit PU is provided with a processing liquid nozzle 132 that supplies a processing liquid for forming a resist film to the substrate rotated by the spin chuck 131. Each processing unit PU forms a resist film on one surface of the unprocessed substrate W (coating process). The substrate W after the coating process with the resist film formed thereon is subjected to exposure processing by the exposure device 500.

The development processing unit 140 performs development processing of the substrate W by supplying a developing solution to the substrate W after the exposure processing of the exposure device 500. The heat treatment section 150 performs heat treatment of the substrate W before and after the coating treatment by the coating treatment section 130, the development treatment by the development treatment section 140, and the exposure treatment by the exposure device 500.

The substrate inspection apparatus 200 performs inspection (defect determination processing) of the substrate W after the resist film is formed by the coating processing section 130. For example, the substrate inspection device 200 performs inspection of the substrate W after the coating process by the coating processing unit 130 and before the exposure process of the exposure device 500. At this time, the user can visually inspect the substrate W by viewing the image displayed on the display unit 280 based on the image data for display.

The transfer device 120 transfers the substrate W determined to be non-defective to the exposure device 500. On the other hand, the transport device 120 does not transport the substrate W determined to be defective to the exposure device 500. This prevents exposure of the defective substrate W.

In addition, the substrate inspection apparatus 200 may inspect the substrate W after the coating processing by the coating processing section 130, after the exposure processing by the exposure device 500, and after the development processing by the development processing section 140. Alternatively, the substrate inspection apparatus 200 may inspect the substrate W after the coating process by the coating processing unit 130 and after the exposure process by the exposure device 500 and before the development process by the development processing unit 140. In such cases, the user can perform a visual inspection of the substrate W by viewing the image based on the display image data generated during the inspection of the substrate W.

In the above substrate processing apparatus 100, a processing unit for forming an anti-reflection film on the substrate W may be provided in the coating processing unit 130. In this case, the heat treatment unit 150 may also perform an adhesion strengthening process to improve the adhesion between the substrate W and the anti-reflection film. In addition, a processing unit for forming a resist cover film for protecting the resist film formed on the substrate W may be provided in the coating processing portion 130.

When the anti-reflection film and the resist cover film are formed on one surface of the substrate W, the substrate W may be inspected by the substrate inspection apparatus 200 after the formation of each film.

In the substrate processing apparatus 100 of this embodiment, the surface state of one surface of the substrate W on which films such as a resist film, an anti-reflection film, and a resist cover film are formed is inspected by the substrate inspection device 200 of FIG. 1. Thereby, in the visual inspection using the image representing one side of the substrate W, it is possible to easily and accurately determine the presence or absence of defects of the film formed on one side of the substrate W. As a result, the occurrence of defective processing of the substrate W is reduced.

[4] Other embodiments (a) In the above embodiment, the width of each unit area UA set on the image based on the actual image data in the X direction is set to one pixel, but the present invention is not limited to this. The width of each unit area UA in the X direction may also have a width of several pixels of about 2 pixels or 3 pixels.

(b) In the first embodiment, in the correction process for generating image data for display, the average pixel value of the unit area UA located in the center of the substrate W among the plurality of unit areas UA is used as the reference value, but the present invention does not Limited to this. As the reference value, the average pixel value of the unit area UA of the pixel position in the predetermined X direction outside the center of the substrate W may also be used.

(c) In the second embodiment, in the correction process for generating the image data for display, the range from the minimum difference to the maximum difference of the unit area UA located in the center of the substrate W among the plurality of unit areas UA is determined as The reference range, but the invention is not limited to this. The range from the minimum difference to the maximum difference of the unit area UA of the pixel position in the predetermined X direction outside the center of the substrate W may also be determined as the reference range.

(d) In the above embodiment, since the imaging unit 240 uses a color imaging element, each pixel data constituting the actual image data includes R pixel values, G pixel values, and B pixel values, but the present invention is not limited to this. It is also possible to use a monochrome imaging device for the imaging unit 240. In this case, in the image based on the image data for display, the average brightness of a plurality of portions of one surface of the substrate W regarded as the X direction is also suppressed.

(e) In the above embodiment, the defect determination process is performed for each substrate W, and the average pixel value is calculated for each of the plurality of unit areas UA, but the present invention is not limited to this. In the case of performing defect determination processing on a plurality of substrates W having a common surface structure, for example, the average pixel of a plurality of unit areas UA can also be calculated from actual image data obtained by photographing a sample substrate or the first inspection substrate W Value, the calculated result is memorized in the memory of the control device 400. In this case, the average pixel value of the plurality of unit areas UA stored in the memory can be used when the defect determination processing of the second and subsequent substrates W is performed. Therefore, it is not necessary to calculate the average pixel value of the plurality of unit areas UA every time the defect determination process is performed. By this, the processing at the time of generating the image data for display after the second piece can be simplified.

Alternatively, the design data predetermined for the average pixel value of the plurality of unit areas UA may be stored in the memory of the control device 400. In this case, the processing at the time of generating the image data for display can also be simplified.

(f) In the method for generating image display data according to the first embodiment, based on the average pixel value shown in FIG. 16 and the smoothed average pixel value shown in FIG. 17, it is used to obtain image data for display Correction process, but the invention is not limited to this. Based on the average pixel value shown in FIG. 7 and the smoothed average pixel value shown in FIG. 9, correction processing for obtaining image data for display may also be performed.

(g) In the method for generating image display data according to the second embodiment, based on the average pixel value shown in FIG. 16 and the smoothed average pixel value shown in FIG. 17, the image data for display is calculated to obtain Evaluation of the deviation, but the invention is not limited to this. Alternatively, based on the average pixel value shown in FIG. 7 and the smoothed average pixel value shown in FIG. 9, a deviation evaluation value for obtaining image data for display may be calculated.

(h) In the substrate inspection apparatus 200 of the above embodiment, the imaging unit 240 has an imaging area extending in one direction, but the present invention is not limited to this. The imaging unit 240 may have a planar imaging area. That is, as the imaging element of the imaging unit 240, a color CCD area sensor or a CMOS area sensor arranged in a matrix of a plurality of pixels may be used.

In this case, for example, by arranging the imaging unit 240 such that the imaging area of the imaging unit 240 covers the entire surface of the substrate W, there is no need to relatively move the imaging unit 240 and the substrate holding device 250 in the front-rear direction. This can shorten the time required for the inspection of the substrate W.

(i) In the above embodiment, the reflection part 230 is provided in the substrate inspection device 200, but the present invention is not limited to this. When the imaging unit 240 is configured to directly receive the light from the substrate W, the reflection unit 230 may not be provided.

(j) In the above embodiment, the moving part 260 is configured to move the substrate holding device 250 relative to the moving part 260, the light projecting part 220, the reflecting part 230, and the imaging part 240, but the present invention is not limited to this. The moving section 260 may be configured to move the light projecting section 220, the reflecting section 230, and the imaging section 240 relative to the substrate holding device 250 in the front-rear direction so that the imaging area of the imaging section 240 passes through the entire surface of the substrate W.

[5] Correspondence between each component of the technical solution and each component of the embodiment The following describes an example in which each component of the technical solution corresponds to each component of the embodiment, but the present invention is not limited to the following examples .

In the above embodiment, the substrate holding device 250 and the control unit 401 are examples of holding units, the imaging unit 240 and the image generating unit 402 are examples of imaging units, and the moving unit 260 and control unit 401 are examples of moving units.

Furthermore, in the first embodiment, the process of smoothing the average pixel value of FIG. 16 by the moving median method is an example of smoothing processing, and in the second embodiment, the average pixel value of FIG. 16 is changed by the moving median The method of smoothing by method is an example of the first smoothing process. In the second embodiment, the deviation evaluation value calculated based on the average pixel value shown in FIG. 16 and the average pixel value after smoothing shown in FIG. 17 is the deviation example.

Furthermore, in the second embodiment, the process of smoothing the deviation evaluation value of FIG. 21 by the moving maximum method is an example of the second smoothing process. In the second embodiment, the deviation evaluation value of FIG. 21 is minimized by moving The process of normal smoothing is an example of the third smoothing process.

As each constituent element of the technical solution, other various elements having the configuration or function described in the technical solution can also be used. [Industry availability]

The invention can be effectively used for surface inspection of various substrates.

100‧‧‧Substrate processing device 110‧‧‧Control device 120‧‧‧Transport device 130‧‧‧Coating processing unit 131‧‧‧Rotating chuck 132‧‧‧Process liquid nozzle 140‧‧‧Development processing unit 150‧ ‧‧Heat treatment part 200‧‧‧Substrate inspection device 210‧‧‧Frame part 211‧‧‧Bottom part 212～215‧‧‧Side part 216‧‧‧Opening part 220‧‧‧Projection part 230‧‧‧Reflection Part 240‧‧‧Camera part 250‧‧‧Substrate holding device 251‧‧‧Drive device 252‧‧‧Rotary holding part 260‧‧‧Moving part 261‧‧‧Guide member 262‧‧‧Move holding part 270‧‧‧ Cut detection unit 280‧‧‧Display unit 400‧‧‧Control device 401‧‧‧Control unit 402‧‧‧Image generation unit 403‧‧‧Judgment unit 404‧‧‧Image judgment memory unit 405‧‧‧Display Image data generation unit 411‧‧‧ smoothing unit 412‧‧‧ correction unit 421‧‧‧ smoothing unit 422‧‧‧ deviation calculation unit 423‧‧‧ deviation maximum calculation unit 424‧‧‧ minimum deviation calculation 425‧‧‧Maximum difference calculation unit 426‧‧‧Minimum difference calculation unit 427‧‧‧Base range determination unit 428‧‧‧ Correction unit 500‧‧‧ Exposure device B1‧‧‧1B reference curve B3max 、B3min‧‧‧Solid line BA‧‧‧Zone zone BDmax, BDmin‧‧‧Solid line G1‧‧‧ 1G reference curve G3max, G3min‧‧‧Point line GDmax, GDmin‧‧‧Point line PI‧‧‧ Pixel P1‧‧‧1st reference curve R3max, R3min‧‧‧ point chain line RB‧‧‧B average pixel value line RDmax, RDmin‧‧‧ point chain line RG‧‧‧G average pixel value line RR‧‧‧R Average pixel value S11～S20‧‧‧Step S20～S31‧‧‧Step UA‧‧‧Unit area UN1, UN2‧‧‧Useless range VP‧‧‧Imaginary point VS1‧‧‧The first virtual surface VS2‧‧‧ 2 Imaginary surface W‧‧‧substrate WC‧‧‧center of substrate W WE1‧‧‧ one end of substrate W WE2‧‧‧‧other end of substrate W

Fig. 1 is an external perspective view of a substrate inspection device according to a first embodiment. FIG. 2 is a schematic side view showing the internal structure of the substrate inspection device of FIG. 1. FIG. 3 is a schematic plan view showing the internal structure of the substrate inspection device of FIG. 1. FIG. 4(a) is a diagram showing an example of an actual image on one side of a substrate, and FIG. 4(b) is a diagram showing an example of a previous image based on image data. FIG. 5 is a schematic plan view showing a state in which the entire surface of a substrate is imaged by an imaging unit in the substrate inspection device of FIG. 1. FIG. 6 is a diagram for explaining a method of generating data for image display according to the first embodiment. 7 is a diagram for explaining a method of generating data for image display according to the first embodiment. FIG. 8 is a diagram for explaining a method of generating data for image display according to the first embodiment. FIG. 9 is a diagram for explaining a method of generating data for image display according to the first embodiment. 10(a) to (d) are diagrams for explaining a method of generating data for image display according to the first embodiment. FIG. 11 is a diagram for explaining a method of generating data for image display according to the first embodiment. FIG. 12 is a diagram for explaining a method of generating data for image display according to the first embodiment. FIG. 13 is a diagram for explaining a method of generating data for image display according to the first embodiment. 14(a) to (d) are diagrams for explaining a method of generating data for image display according to the first embodiment. 15(a) to (d) are diagrams for explaining a method of generating data for image display according to the first embodiment. FIG. 16 is a diagram for explaining a method of generating data for image display according to the first embodiment. FIG. 17 is a diagram for explaining the method of generating image display data according to the first embodiment. FIG. 18 is a diagram for explaining a method of generating image display data according to the first embodiment. FIG. 19 is a block diagram showing the control system of the substrate inspection apparatus of the first embodiment. FIG. 20 is a flowchart of the defect determination process in the first embodiment. FIG. 21 is a diagram for explaining a method of generating data for image display according to the second embodiment. Fig. 22 is a diagram for explaining a method of generating data for image display according to the second embodiment. FIG. 23 is a diagram for explaining a method of generating data for image display according to the second embodiment. FIG. 24 is a diagram for explaining a method of generating data for image display according to the second embodiment. FIG. 25 is a block diagram showing the functional configuration of the display image data generating section of the second embodiment. Fig. 26 is a flowchart of defect determination processing in the second embodiment. FIG. 27 is a schematic block diagram showing the overall configuration of the substrate processing apparatus according to the third embodiment.

S11~S20‧‧‧Step

Claims (18)

A substrate inspection device includes: a holding portion that holds a substrate; an imaging portion that photographs a surface of the substrate held by the holding portion to generate actual image data representing an image of the surface of the substrate; a smoothing portion that For each of the plurality of unit areas arranged in the first diameter direction of the substrate on the image based on the actual image data, the average value of the plurality of pixels constituting the unit area is calculated as the average pixel value, and for the plurality of units The average pixel value of the area is smoothed; and a correction section that calculates the average pixel value after the smoothing processing of the unit area predetermined in the plurality of unit areas and the average after the smoothing processing of each unit area The difference of the pixel values, and each pixel value in the band-shaped region extending parallel to the second diameter direction orthogonal to the first diameter direction from each unit area is added to the difference corresponding to the unit area. The substrate inspection apparatus according to claim 1, wherein the above-mentioned smoothing processing is smoothing processing using a moving median method. The substrate inspection device according to claim 2, wherein the film having a periodic pattern in the first diameter direction formed on the one surface of the substrate has a width used for smoothing processing by the moving median method is larger than the above 1 The period of the above pattern in the diameter direction. The substrate inspection device according to any one of claims 1 to 3, wherein each pixel constituting each of the plurality of unit areas includes R pixels, B pixels, and G pixels, and the smoothing section performs the smoothing for each pixel type In the processing, the correction unit performs the calculation process of the plurality of differences for each pixel type, and performs the addition process of the plurality of differences for each pixel type. A substrate inspection device includes: a holding portion that holds a substrate; an imaging portion that photographs a surface of the substrate held by the holding portion to generate actual image data representing an image of the surface of the substrate; a smoothing portion that For each of the plurality of unit areas arranged in the first diameter direction of the substrate on the image based on the actual image data, the average value of the plurality of pixels constituting the unit area is calculated as the average pixel value, and for the plurality of units The average pixel value of the area is subjected to the first smoothing process using the moving median method; the deviation calculation unit calculates the average pixel value before the first smoothing process of each unit area and the average pixel after the first smoothing process The difference between the values is used as a deviation; the maximum deviation calculation unit calculates the plurality of deviations after the second smoothing process by performing the second smoothing process using the moving maximum method on the deviations of the plurality of unit areas, As a plurality of deviation maximum values; a deviation minimum value calculation unit that calculates the plurality of deviations after the third smoothing process by performing the third smoothing process using the moving minimum method on the deviations of the plurality of unit areas, as A plurality of minimum deviations; a maximum difference calculation unit that calculates the level after the first smoothing process in each unit area The average pixel value and the sum of the deviation maximum value are regarded as the maximum difference; the difference minimum calculation unit calculates the average pixel value after the first smoothing process of each unit area and the minimum deviation The added value is regarded as the minimum difference; the reference range determination unit determines the range corresponding to the predetermined minimum unit area among the plurality of unit areas as the reference range; and The correction unit performs correction so that the range corresponding to the minimum value of the difference from each unit area to the maximum value of the difference coincides with the reference range, and the second area orthogonal to the first diameter direction from each unit area to the second The pixel values in the band-shaped regions extending in parallel in the diameter direction are suitable for correction in the corrected range. The substrate inspection device according to claim 5, wherein a film having a periodic pattern in the first diameter direction is formed on the one surface of the substrate, using the first smoothing process of the moving median method, using the moving maximum method The width used in the second smoothing process and the third smoothing process using the above-mentioned moving minimum method is larger than the period of the pattern in the first diameter direction. The substrate inspection apparatus according to claim 5 or 6, wherein each pixel constituting each of the plurality of unit areas includes R pixels, B pixels, and G pixels, and the smoothing section performs the first smoothing process for each pixel type, The deviation calculation unit performs the calculation process of the plurality of deviations for each pixel type, and the deviation maximum calculation unit performs the calculation process of the plurality of maximum differences for each pixel type, The minimum deviation calculation unit performs the calculation process of the plurality of minimum differences for each pixel type, and the maximum difference calculation unit performs the calculation process of the plurality of maximum differences for each pixel type. The minimum value calculation unit performs the calculation process of the plurality of difference minimum values for each pixel type, the reference range determination unit performs the determination process of the reference range for each pixel type, and the correction unit performs correspondence for each pixel type The correction process in which the range of the minimum difference to the maximum difference in each unit area is consistent with the reference range, and the correction process of adapting each pixel value in each band region to the corrected range. The substrate inspection device according to any one of claims 1 to 3, 5, or 6, wherein the smoothing section is a part of the plurality of unit areas, that is, the substrate located on the image based on the actual image data The average pixel values of the plurality of unit regions at one end in the first diameter direction should be calculated separately, based on the estimation of the plurality of average pixel values calculated for the plurality of unit regions located at the part adjacent to the one end, and determined based on the estimation result Each corresponds to a plurality of average pixel values of the plurality of unit regions located at the one end. The substrate inspection apparatus according to any one of claims 1 to 3, 5, or 6, wherein the imaging section has a linear imaging area on the one surface of the substrate held by the holding section The first diametric direction extends in parallel, and the substrate inspection device further includes a moving portion that passes the imaging area in the second diametric direction. The above-mentioned one side of the substrate held by the holding section moves the imaging section and the holding section relatively. A substrate processing apparatus comprising: a coating processing section which forms a film on one surface of a substrate by supplying a processing liquid to one surface of the substrate; such as the substrate inspection of any one of claims 1 to 3, 5 or 6 An apparatus that inspects a substrate on which a film is formed by the coating processing section; and a transport device that transports the substrate between the coating processing section and the substrate inspection apparatus. A substrate inspection method including the following steps: a step of generating actual image data, which takes a side of the substrate held by the holding portion, generates actual image data representing an image of the above side of the substrate; a step of smoothing processing, For each of a plurality of unit areas arranged in the first diameter direction of the substrate on the image based on the actual image data, the average value of the plurality of pixels constituting the unit area is calculated as the average pixel value. The average pixel values of the plurality of unit areas are smoothed; and an addition step, which calculates the average pixel value after the smoothing processing of the predetermined unit area in the plurality of unit areas, and the smoothing of each unit area The difference between the average pixel values after processing, and each pixel value in the band-shaped region extending parallel to the second diameter direction orthogonal to the first diameter direction from each unit area, plus the difference corresponding to the unit area the amount. The substrate inspection method according to claim 11, wherein the smoothing processing is smoothing processing using a moving median method. The substrate inspection method according to claim 12, wherein the film formed on the above-mentioned one side of the substrate and having a periodic pattern in the first diameter direction is used for the smoothing process using the moving median method is larger than the above-mentioned 1 The period of the above pattern in the diameter direction. The substrate inspection method according to any one of claims 11 to 13, wherein each pixel constituting each of the plurality of unit areas includes R pixels, B pixels, and G pixels, and the step of performing the above-described smoothing process includes each pixel The above-mentioned smoothing process is performed for each type, and the adding step includes performing the calculation processing of the plurality of differences for each pixel type, and performing the addition processing of the plurality of differences for each pixel type. A substrate inspection method, comprising the steps of: photographing a surface of a substrate held by a holding portion, and generating actual image data representing an image of the above surface of the substrate; aiming at an image based on the actual image data arranged on the substrate Each of the plurality of unit areas in the first diameter direction calculates the average value of the plurality of pixels constituting the unit area, and as the average pixel value, applies the moving median method to the average pixel value of the plurality of unit areas 1 smoothing process; calculate the average pixel value of each unit area before the first smoothing process, and the first The difference between the average pixel values after the smoothing process is used as the deviation; by performing the second smoothing process using the moving maximum method on the deviation of the plurality of unit areas, the plurality of deviations after the second smoothing process are calculated, As the maximum value of the plural deviations; by performing the third smoothing process using the moving minimum method on the deviations of the plural unit areas, the plural deviations after the third smoothing treatment are calculated as the minimum values of the plural deviations; The sum of the average pixel value after the first smoothing process of each unit area and the maximum value of the deviation is the maximum value of the difference; the average pixel value after the first smoothing process of each unit area is calculated, and The sum of the above minimum deviations is taken as the minimum difference; it is determined that the range corresponding to the predetermined minimum unit area of the plurality of unit areas above the maximum difference is used as the reference range; and the correction step , Which is corrected so that the range corresponding to the minimum value of the difference between each unit area to the maximum value of the difference is consistent with the reference range, and so that the second diameter orthogonal to the above-mentioned first diameter direction from each unit area Each pixel value in each band-shaped area extending in a parallel direction is suitable for correction in the corrected range. The substrate inspection method according to claim 15, wherein a film having a periodic pattern in the first diameter direction is formed on the one surface of the substrate, using the first smoothing process of the moving median method, using the moving maximum method The width used in the second smoothing process and the third smoothing process using the above-mentioned moving minimum method is larger than the period of the pattern in the first diameter direction. The substrate inspection method according to claim 15 or 16, wherein each pixel constituting each of the plurality of unit areas includes R pixels, B pixels, and G pixels, and the step of performing the first smoothing process includes performing for each pixel type In the first smoothing process, the step of calculating the deviation includes calculating the plurality of deviations for each pixel type, and the step of calculating the maximum deviation includes performing the plurality of maximum differences for each pixel type The calculation process, the step of calculating the minimum deviation includes the calculation process of the plurality of minimum values for each pixel type, and the step of calculating the maximum difference includes the plurality of differences for each pixel type The calculation of the maximum value of the amount, the step of calculating the minimum value of the difference includes the calculation of the plurality of minimum values of the difference for each pixel type, and the step of determining the reference range includes the above reference for each pixel type For the range determination process, the above-mentioned correction step includes performing correction processing for each pixel type to make the range corresponding to each unit area from the minimum difference to the maximum difference equal to the reference range, and to make the Each pixel value is suitable for the correction process of the corrected range. A substrate processing method, comprising the steps of: forming a film on one surface of a substrate by supplying a processing liquid to one surface of the substrate; and Using the substrate inspection method according to any one of claims 11 to 13, 15, or 16, inspect the substrate on which the film is formed on the one side.

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