JP2016070730A - Image acquisition device and image acquisition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately acquire an image indicating a portion in a subject layer that has changed in quality.SOLUTION: In this image acquisition device, a resist layer on a base material 9, a portion of which has changed in quality by irradiation of light, is assumed to be an object to be image-captured. In acquiring an image, an irradiation angle θ1 formed by an optical axis J1 leading from a light irradiation unit 31 to a linear image-capturing area 90 and a normal line N of the resist layer and a detection angle θ2 formed by an optical axis J2 leading from the image-capturing area 90 to a line sensor 32 and the normal line N are set to prescribed set angles. Light of a wavelength having transmissivity to the resist layer and not included in the photosensitive wavelength band of the resist layer is radiated from the light irradiation unit 31, while the base material 9 is moved in a direction intersecting the image-capturing area 90, whereby an image is acquired by the line sensor 32. In this way, an image indicating the photosensitized portion of the resist layer can be appropriately acquired without affecting the non-photosensitized portion.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image acquisition device and an image acquisition method.

  Conventionally, various patterns formed on a substrate have been inspected. For example, in the inspection of the pattern of the transparent electrode formed on the base material, the continuity inspection is performed using a metal electrode connected to the transparent electrode via a transparent wiring. However, when a defect has occurred in the pattern, the position and type cannot be confirmed only by the continuity test, and it is difficult to improve the yield reduction due to the defect. Therefore, Patent Document 1 proposes an apparatus that acquires an inspection image of a pattern of a transparent electrode formed on a substrate. In the apparatus of Patent Document 1, the setting angle of the irradiation angle formed by the optical axis from the light irradiation unit to the imaging region and the normal of the base material is obtained, the irradiation angle is set to the setting angle, and the imaging sensor reaches the line sensor. By setting the detection angle between the optical axis and the normal to the set angle, an inspection image with high contrast is acquired. Patent Document 2 discloses a method of optically inspecting a photosensitive portion of a resist layer using light having a wavelength of 522 to 645 nm after exposing the resist layer on the substrate.

JP 2012-251808 A JP 2004-347913 A

  By the way, when forming a pattern on a base material, the resist layer pattern is formed by performing an exposure process and a development process on the base material on which the resist layer is formed. In this case, before performing the development process, it is possible to quickly determine whether there is an abnormality in the exposure process by acquiring an image showing a photosensitive portion of the resist layer as in Patent Document 2. However, when the wavelength of light 522 to 645 nm used in the method of Patent Document 2 is included in the photosensitive wavelength band of the resist layer, an image can be displayed without affecting the non-photosensitive portion of the resist layer. I can't get it. In addition to the image showing the photosensitive part of the resist layer, it may be beneficial to obtain an image showing the altered part in a layer partly altered by a predetermined process.

  The present invention has been made in view of the above problems, and an object of the present invention is to appropriately acquire an image showing a part that has been altered in a layer partly altered by a predetermined process.

  The invention according to claim 1 is an image acquisition device, wherein a layer formed of another material on a substrate or a layer including the surface of the substrate itself is used as a target layer. A support part that supports the base material, the part of which has been altered by a predetermined process, a light irradiation part that emits light having a wavelength that is transparent to the target layer, and a linear imaging region that is irradiated with the light A line sensor that receives light from the light source, a moving mechanism that moves the base material relative to the imaging region in a direction intersecting the imaging region, and an optical axis that extends from the light irradiation unit to the imaging region. An angle for changing the irradiation angle and the detection angle while maintaining the irradiation angle formed by the normal line of the target layer and the detection angle formed by the optical axis extending from the imaging region to the line sensor and the normal line equal to each other. And a change mechanism.

  The invention according to claim 2 is the image acquisition device according to claim 1, wherein the target layer is a layer formed of a photosensitive material, and the part of the target layer is made of light. The wavelength of light emitted from the light irradiation unit is not included in the photosensitive wavelength band of the photosensitive material.

  Invention of Claim 3 is an image acquisition apparatus of Claim 2, Comprising: The said target layer is a layer formed with the photoresist on the said base material.

  Invention of Claim 4 is an image acquisition apparatus of Claim 1, Comprising: The said object layer is a layer of the optical waveguide provided in the said base material itself, The said part of the said object layer is It is altered by the addition of other materials by doping.

  The invention according to claim 5 is an image acquisition method, wherein a layer formed of another material on a substrate or a layer including the surface of the substrate itself is used as a target layer. An optical axis extending from a light irradiation unit that emits light having a wavelength that is transmissive to the target layer to a linear imaging region, and the target layer A step of obtaining a set angle of an irradiation angle formed with the normal line, and setting the irradiation angle to the set angle, and a detection angle formed between the optical axis from the imaging region to the line sensor and the normal line is also the set angle. And a step of acquiring the image by moving the base material relative to the imaging region in a direction intersecting the imaging region.

  The invention according to claim 6 is the image acquisition method according to claim 5, wherein the target layer is a layer formed of a photosensitive material, and the part of the target layer is made of light. The wavelength of light emitted from the light irradiation unit is not included in the photosensitive wavelength band of the photosensitive material.

  The invention according to claim 7 is the image acquisition method according to claim 6, wherein the target layer is a layer formed of a photoresist on the base material.

  Invention of Claim 8 is the image acquisition method of Claim 5, Comprising: The said object layer is a layer of the optical waveguide provided in the said base material itself, The said part of the said object layer is It is altered by the addition of other materials by doping.

  ADVANTAGE OF THE INVENTION According to this invention, the image which shows the part which changed in the object layer can be acquired appropriately.

It is a figure which shows the structure of a pattern formation system. It is a front view which shows an image acquisition part. It is a block diagram which shows the function structure of a process monitoring apparatus. It is a figure which shows the flow of the process which forms a pattern. It is a figure which shows the flow of the process which forms a pattern. It is sectional drawing which shows a base material. It is a figure which shows the flow of the process which acquires an image. It is a figure which shows the relationship between the contrast of the photosensitive pattern in each wavelength, and an irradiation angle. It is a photograph which shows a photosensitive pattern image. It is a figure which shows the structure of an image acquisition apparatus. It is sectional drawing which shows a base material.

  FIG. 1 is a diagram showing a configuration of a pattern forming system 1 according to an embodiment of the present invention. The pattern forming system 1 forms a pattern by etching on a film-like substrate 9. The main body of the base material 9 is formed of a resin transparent to visible light and is a strip-shaped continuous sheet. The base material 9 has a transparent conductive film formed of, for example, ITO (Indium Tin Oxide), and one main surface of the base material 9 is the surface of the transparent conductive film. On the main surface of the substrate 9, that is, on the transparent conductive film, a layer of photoresist that is a photosensitive material (hereinafter referred to as “resist layer”) is formed in advance.

  The pattern forming system 1 includes a transport mechanism 11, an exposure device 21, a buffer device 12, a developing device 22, an etching device 23, and a resist stripping device 24. The transport mechanism 11 includes a supply unit 111, a collection unit 112, and a plurality of transport rollers 110. The supply unit 111 holds the base material 9 before pattern formation as a roll, and sequentially draws out each part of the base material 9 (that is, a plurality of parts continuously present on the belt-like base material 9) from the roll. The collection unit 112 sequentially collects the portions of the base material 9 after pattern formation as rolls. Thus, the pattern forming system 1 employs a so-called roll-to-roll method in which each part of the base material 9 drawn from the roll by the supply unit 111 moves to the collection unit 112 and is wound in a roll shape. Is done. The plurality of transport rollers 110 are arranged along the movement path of the base material 9 and support the base material 9 on the way of movement from below. That is, the plurality of transport rollers 110 are support portions that support the base material 9. In FIG. 1, the movement path of the base material 9 is illustrated in two upper and lower stages.

  The exposure device 21, the buffer device 12, the developing device 22, the etching device 23, and the resist stripping device 24 are arranged in this order from the supply unit 111 toward the recovery unit 112. As will be described later, the exposure device 21, the developing device 22, the etching device 23, and the resist stripping device 24 expose the pattern on the resist layer formed on the transparent conductive film, develop the resist layer, etch the transparent conductive film, and Then, the resist layer remaining on the main surface is peeled off. That is, in the pattern forming system 1, a pattern is formed by photolithography. In the buffer device 12, a part of the base material 9 is accumulated so that the time from exposure of the pattern to the resist layer until development is approximately constant at each part of the base material 9.

  The pattern forming system 1 further includes a computer 10 and four image acquisition units 3a to 3d. The computer 10 is responsible for overall control of the pattern forming system 1. The image acquisition unit 3 a is disposed between the exposure device 21 and the buffer device 12, and the image acquisition unit 3 b is disposed between the developing device 22 and the etching device 23. The image acquisition unit 3 c is disposed between the etching device 23 and the resist stripping device 24, and the image acquisition unit 3 d is disposed between the resist stripping device 24 and the collection unit 112. Since the four image acquisition units 3a to 3d have the same structure, in the following description regarding the structure of the image acquisition units 3a to 3d, the four image acquisition units 3a to 3d are collectively referred to as “image acquisition unit 3”. To do.

  FIG. 2 is a front view showing one image acquisition unit 3. The image acquisition unit 3 includes a light irradiation unit 31 that emits light toward the imaging region 90 on the substrate 9, a line sensor 32 that receives reflected light from the imaging region 90, and light irradiation by the light irradiation unit 31. An angle changing mechanism 33 that changes the angle and the detection angle by the line sensor 32 is provided. Here, the irradiation angle is an angle θ <b> 1 formed by the optical axis J <b> 1 extending from the light irradiation unit 31 to the imaging region 90 and the normal line N (also a normal line of the resist layer) of the base material 9. The detection angle is an angle θ2 formed by the optical axis J2 extending from the imaging region 90 to the line sensor 32 and the normal N.

  The light irradiation unit 31 emits light having a predetermined wavelength. Light is applied to at least the linear imaging region 90. The light irradiation unit 31 uniformizes light from the plurality of LEDs arranged in the width direction of the base material 9 (direction perpendicular to the paper surface of FIG. 2), and the imaging that extends in the width direction of the base material 9. An optical system leading to the region 90 is provided. The line sensor 32 includes a one-dimensional imaging device and an optical system that optically conjugates the imaging region 90 and the light receiving surface of the imaging device. Note that an autofocus mechanism that integrally moves the light irradiation unit 31, the line sensor 32, and the angle changing mechanism 33 in the direction of the normal line N of the substrate 9 may be provided in the image acquisition unit 3.

  The substrate 9 is moved in a direction intersecting the imaging region 90 by the transport mechanism 11 including the transport roller 110. That is, the transport mechanism 11 is a mechanism that moves the base material 9 relative to the imaging region 90. In parallel with the movement of the base material 9, the line sensor 32 repeatedly acquires a line image of the linear imaging region 90 at a high speed, and acquires a two-dimensional captured image. In the present embodiment, the base material 9 moves in a direction perpendicular to the imaging region 90, but the imaging region 90 may be inclined with respect to the moving direction. The transport mechanism 11 serves as a moving mechanism in the image acquisition unit 3.

  The angle changing mechanism 33 changes the irradiation angle θ1 and the detection angle θ2 while maintaining the irradiation angle θ1 and the detection angle θ2 equal. Therefore, the size of the detection angle in the following description is also the size of the irradiation angle, and the size of the irradiation angle is also the size of the detection angle. The light irradiation unit 31 and the line sensor 32 are supported by the base wall 34 via the angle changing mechanism 33. The base wall 34 is a plate member that is parallel to the normal direction and the moving direction of the substrate 9 (that is, perpendicular to the width direction).

  The base wall 34 is provided with an arc-shaped first opening 341 and a second opening 342 centered on the imaging region 90. The angle changing mechanism 33 includes a motor 35 for moving the light irradiation unit 31 along the first opening 341, a guide unit, a rack, and a pinion (not shown), and a line sensor along the second opening 342. And a motor 36 for moving 32, and a guide portion, a rack and a pinion (not shown).

  FIG. 3 is a block diagram illustrating a functional configuration realized by the computer 10. The computer 10 includes a defect detection unit 41 and a display unit 42. The defect detection unit 41 detects the occurrence of process abnormality based on the images input from the image acquisition units 3 a to 3 d and notifies the operator via the display unit 42. In the pattern forming system 1, a process monitoring device 4 that monitors a process when forming a pattern is constructed by the image acquisition units 3 a to 3 d, the defect detection unit 41, and the display unit 42. Details of processing by each component of the process monitoring apparatus 4 will be described later.

  4 and 5 are diagrams showing a flow of processing in which the pattern forming system 1 forms a pattern by etching on the substrate 9. 4 and 5 show the flow of processing performed on each part of the base material 9 drawn out by the supply unit 111. Actually, FIG. 4 and FIG. 4 and steps S11 to S26 of FIG. 5 are performed in parallel. The pattern forming process includes a process monitoring process performed by the process monitoring apparatus 4.

  FIG. 6 is a cross-sectional view showing the substrate 9. As shown in the uppermost stage of FIG. 6, the substrate 9 has a transparent resin film 91 and a transparent conductive film 92, and the transparent conductive film 92 is laminated on almost the entire resin film 91. A resist layer 93 is formed in advance on the main surface of the substrate 9, that is, on the transparent conductive film 92. Each part of the base material 9 drawn out by the supply unit 111 in FIG. 1 moves to the exposure apparatus 21.

  The exposure apparatus 21 includes, for example, a light source unit that emits light having a predetermined wavelength (hereinafter referred to as “exposure light”) and a mask unit 211 on which a predetermined light shielding pattern is formed (see the second stage from the top in FIG. 6). ). The wavelength of the exposure light is included in the wavelength band of light for exposing the resist layer 93, that is, the photosensitive wavelength band, and the exposure light is applied to the resist layer 93 on the substrate 9 through the mask portion 211. In the resist layer 93, the exposure light is not irradiated to the part shielded by the light shielding pattern, and only the part other than the part is irradiated with the exposure light. The portion irradiated with the exposure light is exposed to light, and a pattern 930 (hereinafter referred to as “photosensitive pattern 930”) of the exposed portion is formed in the resist layer 93 (step S11). A part of the base material 9 (hereinafter referred to as “target part”) for which the exposure process by the exposure apparatus 21 has been completed is moved to the image acquisition unit 3a and a captured image (hereinafter, “ (Referred to as “photosensitive pattern image”) (step S12).

  FIG. 7 is a diagram illustrating a flow of processing in which the image acquisition unit 3a acquires an image. In the image acquisition unit 3a, the setting angle of the irradiation angle and the detection angle that can increase the contrast of the photosensitive pattern 930 in the captured image is obtained (step S121). Here, the contrast of the photosensitive pattern 930 is the ratio of the gradation difference (absolute value) between the photosensitive pattern 930 and the background area (non-photosensitive portion) in the captured image to the entire gradation range. The contrast of the photosensitive pattern 930 is caused by a difference in optical constants (refractive index, etc.) between the photosensitive pattern 930 and the background area.

  FIG. 8 is a diagram showing the relationship between the contrast of the photosensitive pattern 930 at each wavelength and the irradiation angle (and detection angle). The relationship shown in FIG. 8 is obtained by a predetermined calculation for a resist layer 93 of a certain type and thickness. From FIG. 8, it can be seen that the contrast of the photosensitive pattern 930 in each wavelength of light depends on the irradiation angle. That is, when the irradiation angle is changed, the optical path length of the light passing through each region is changed, and the light interference state is changed. Therefore, by appropriately selecting the irradiation angle and the detection angle, it is possible to obtain high contrast using only light of one wavelength from the light irradiation unit 31.

  Here, the light irradiation unit 31 in the image acquisition unit 3 a is transparent to the resist layer 93 and emits light having a wavelength not included in the photosensitive wavelength band of the resist layer 93. In step S121, the angle of the irradiation angle that maximizes the contrast of the photosensitive pattern 930 at the wavelength of the light is obtained as the set angle. Note that the image acquisition unit 3a may obtain a set angle at which the contrast of the photosensitive pattern 930 is increased by acquiring a captured image of the photosensitive pattern 930 while changing the irradiation angle and the detection angle as advance preparation.

  When the set angle is obtained, the irradiation angle and the detection angle are set to the set angle by controlling the angle changing mechanism 33 (step S122). Subsequently, emission of light from the light irradiation unit 31 is started, and the substrate 9 is continuously moved along the movement path by the transport mechanism 11. In parallel with the movement of the base material 9, the line sensor 32 repeatedly acquires a line image of the linear imaging region 90 at a high speed. Thereby, a two-dimensional captured image (that is, a photosensitive pattern image) showing the photosensitive pattern 930 is acquired (step S123).

  FIG. 9 is a photograph showing a part of the photosensitive pattern image. As shown in FIG. 9, a relatively high contrast is obtained in the photosensitive pattern image. The data of the photosensitive pattern image is output to the defect detection unit 41.

  In the present embodiment, since the same set angle is used for the entire base material 9, the above steps S121 and S122 are performed only for the first part of the base material 9. Further, since the exposure device 21 and the image acquisition unit 3a are continuously arranged in the movement path of the belt-like substrate 9, the movement speed of the substrate 9 in the exposure device 21 and the image acquisition unit 3a is the same. Actually, after the exposure process for one part of the base material 9 is completed in the exposure apparatus 21, image acquisition is performed when the base material 9 is continuously moved until the next part reaches below the mask portion 211. The photosensitive pattern image of the other part is acquired by the unit 3a.

  In the defect detection unit 41, the photosensitive pattern image is compared with the design data (or master image) (FIG. 4: step S13). Specifically, each pattern element is specified in the photosensitive pattern image, and the width of each position of the pattern element is acquired. In the present embodiment, the mask unit 211 of the exposure apparatus 21 shows a number of electrode and wiring patterns, and the pattern elements are portions corresponding to the electrodes and wirings. Further, the width of the pattern element in the design data is specified as the design width, and the upper limit value and the lower limit value of the line width are obtained by multiplying the design width by a predetermined upper limit coefficient and lower limit coefficient. Then, the width of each position of the pattern element in the photosensitive pattern image is compared with the upper limit value and the lower limit value of the line width, and when the width of the position is larger than the upper limit value or smaller than the lower limit value, It is detected that a defect at the position has occurred. In this way, the overall width of all pattern elements in the photosensitive pattern image is compared with the upper and lower limits of the corresponding line width. The line width inspection may be performed only in a predetermined region (the same applies hereinafter). Moreover, in step S13, the defect in the attention site | part of the base material 9 may be detected by acquiring the image which shows the difference of the photosensitive pattern image and the image which design data shows.

  When a defect is detected, for example, a photosensitive pattern image is displayed on the display unit 42 while making it possible to identify the defect position by surrounding it with a line of a predetermined color. The operator determines the presence or absence of an abnormality in the exposure process of the exposure apparatus 21 by confirming the type and number of defects displayed on the display unit 42, and the operation of the pattern forming system 1 as necessary. To stop. If no defect is detected, a message to that effect is displayed. As described above, the comparison result between the photosensitive pattern image and the design data is displayed on the display unit 42 and notified to the operator (step S14). Since the photosensitive pattern image is also used in processing described later, it is stored in the defect detection unit 41 (the same applies to other pattern images). The comparison result may be displayed on the display unit 42 only when a defect is detected (the same applies to steps S18, S22, and S26 described later).

  The site of interest of the substrate 9 moves to the developing device 22 via the buffer device 12. The developing device 22 includes, for example, a developer nozzle and a pure water nozzle. The developer is ejected toward the resist layer 93 of the base material 9 by the developer nozzle. As a result, the photosensitive portion of the resist layer 93 is removed, and the resist layer 93 is developed (see the third row from the top in FIG. 6). The resist layer 93 may be one in which a non-photosensitive portion is removed by a developer. Pure water is ejected from the pure water nozzle to the main surface of the substrate 9 to clean the main surface. In this way, the development process is performed, and a pattern 931 (hereinafter referred to as “resist pattern 931”) of the resist layer 93 remaining on the main surface is formed (step S15).

  The region of interest where the resist pattern 931 is formed moves to the image acquisition unit 3b. In the image acquisition unit 3b, the irradiation angle and the detection angle are set to predetermined angles, and a captured image showing the resist pattern 931 (hereinafter, referred to as “resist pattern image”) by the same operation as Step S123 in FIG. Is acquired (step S16).

  In addition, in principle, each part of the base material 9 moves continuously between the buffer device 12 and the collection unit 112 in the movement path of the belt-like base material 9. Therefore, the process for one part of the base material 9 by the developing device 22 and the image acquisition process for the other part of the base material 9 by the image acquisition unit 3b are performed in parallel (etching device 23, resist stripping). The same applies to the device 24 and the image acquisition units 3c and 3d). In the pattern forming system 1, the buffer device 12 is provided between the image acquisition unit 3 a and the developing device 22, so that the buffer device 12 is moved (stepped) by the exposure device 21 while moving the base material 9 by a certain distance. It is possible to continuously move the substrate 9 at a constant speed between the recovery unit 112 and the recovery unit 112.

  In the defect detection unit 41, the resist pattern image is compared with the photosensitive pattern image acquired in step S12 (step S17). Specifically, each pattern element is specified in the resist pattern image, and the width of each position of the pattern element is acquired. Further, the width of the pattern element in the photosensitive pattern image is specified as the reference width, and the upper limit value and the lower limit value of the line width are obtained by multiplying the reference width by a predetermined upper limit coefficient and lower limit coefficient. Then, the width of each position of the pattern element in the resist pattern image is compared with the upper limit value and the lower limit value of the line width, and when the width of the position is larger than the upper limit value or smaller than the lower limit value, It is detected that a defect at the position has occurred. In this way, the entire widths of all pattern elements in the resist pattern image are compared with the upper and lower limits of the corresponding line width. In step S17, a defect in the target region of the substrate 9 may be detected by acquiring an image indicating the difference between the resist pattern image and the photosensitive pattern image (the same applies to steps S21 and S25 described later).

  When a defect is detected, for example, a resist pattern image is displayed on the display unit 42 while making it possible to identify the defect position by surrounding it with a line of a predetermined color. The operator determines the presence or absence of an abnormality in the developing process of the developing device 22 by checking the type and number of defects displayed on the display unit 42, and operates the pattern forming system 1 as necessary. To stop. If no defect is detected, a message to that effect is displayed. As described above, the comparison result between the resist pattern image and the photosensitive pattern image is displayed on the display unit 42 and notified to the operator (step S18).

  The site of interest of the substrate 9 moves to the etching device 23. The etching apparatus 23 includes, for example, an etching solution nozzle and a pure water nozzle. Etching liquid is ejected toward the main surface of the substrate 9 by the etching liquid nozzle. As a result, the portion of the transparent conductive film 92 not covered with the resist pattern 931 is removed (etched) (see the fourth row from the top in FIG. 6). Pure water is ejected from the pure water nozzle to the main surface of the substrate 9 to clean the main surface. Thus, an etching process is performed with respect to the main surface of the base material 9 (step S19).

  The site of interest subjected to the etching process moves to the image acquisition unit 3c. In the image acquisition unit 3c, the irradiation angle and the detection angle are set to predetermined angles, and a captured image is acquired by the same operation as Step S123 in FIG. 7 (Step S20). The captured image is a pattern image showing the main surface of the substrate 9 after the etching process and before the resist stripping process described later, and is hereinafter referred to as a “pattern image immediately after the etching”.

  In the defect detection unit 41, the pattern image immediately after the etching is compared with the resist pattern image acquired in step S16 (step S21). Specifically, each pattern element is specified in the pattern image immediately after etching, and the width of each position of the pattern element is acquired. Further, the width of the pattern element in the resist pattern image is specified as the reference width, and the upper limit value and the lower limit value of the line width are acquired by multiplying the reference width by a predetermined upper limit coefficient and lower limit coefficient. Then, the width of each position of the pattern element in the pattern image immediately after the etching is compared with the upper limit value and the lower limit value of the line width, and when the width of the position is larger than the upper limit value or smaller than the lower limit value It is detected that a defect has occurred at the position. In this way, the entire widths of all pattern elements in the pattern image immediately after etching are compared with the upper and lower limits of the corresponding line width.

  When a defect is detected, for example, the pattern image immediately after etching is displayed on the display unit 42 while making it possible to identify the defect position by surrounding it with a line of a predetermined color. The operator determines the presence / absence of abnormality in the etching process of the etching apparatus 23 by confirming the type and number of defects displayed on the display unit 42, and operates the pattern forming system 1 as necessary. To stop. If no defect is detected, a message to that effect is displayed. As described above, the comparison result between the pattern image immediately after etching and the resist pattern image is displayed on the display unit 42 and notified to the operator (step S22).

  The site of interest of the substrate 9 moves to the resist stripping device 24. The resist stripping device 24 includes, for example, a stripping liquid nozzle and a pure water nozzle. The stripping liquid is ejected toward the main surface of the substrate 9 by the stripping liquid nozzle. As a result, the resist pattern 931 is peeled off from the main surface of the substrate 9 (see the lowermost stage in FIG. 6). Pure water is ejected from the pure water nozzle to the main surface of the substrate 9 to clean the main surface. In this way, the resist stripping process is performed on the main surface of the substrate 9, and the pattern 921 of the transparent conductive film 92 remaining on the main surface of the resin film 91 appears on the surface of the substrate 9 (step S23). . In the pattern 921 obtained by etching the transparent conductive film 92, a large number of transparent electrodes are arranged. Hereinafter, the pattern 921 is referred to as a “transparent electrode pattern 921”. The site of interest subjected to the resist stripping process moves to the image acquisition unit 3d, and a captured image (hereinafter referred to as “electrode pattern image”) showing the transparent electrode pattern 921 is acquired (step S24).

  In the image acquisition unit 3d, processing according to the image acquisition processing of FIG. 7 is performed. Specifically, the setting angle of the irradiation angle and the detection angle that can increase the contrast of the transparent electrode pattern 921 in the captured image is obtained (step S121). Here, the contrast of the transparent electrode pattern 921 is the ratio of the gradation difference (absolute value) between the transparent electrode pattern 921 and the background region (resin film 91) in the captured image to the entire gradation range. The set angle at which the contrast of the transparent electrode pattern 921 is increased is obtained in advance by a predetermined calculation or by acquiring a captured image of the transparent electrode pattern 921 while changing the irradiation angle and the detection angle as advance preparation. .

  In the image acquisition unit 3d, the irradiation angle and the detection angle are set to the set angles by controlling the angle changing mechanism 33 (step S122). In the present embodiment, since the same set angle is used for the entire base material 9, steps S121 and S122 are performed until the first part of the base material 9 reaches the image acquisition unit 3d. . In the line sensor 32, the line image of the linear imaging region 90 is repeatedly acquired at high speed in parallel with the continuous movement of the base material 9 by the transport mechanism 11. Thereby, a two-dimensional captured image (that is, an electrode pattern image) showing the transparent electrode pattern 921 is acquired (step S123).

  In the defect detection unit 41, the electrode pattern image is compared with the pattern image immediately after etching acquired in step S20 (FIG. 5: step S25). Specifically, each pattern element is specified in the electrode pattern image, and the width of each position of the pattern element is acquired. Further, the width of the pattern element in the pattern image immediately after etching is specified as the reference width, and the upper limit value and the lower limit value of the line width are obtained by multiplying the reference width by a predetermined upper limit coefficient and lower limit coefficient. . Then, the width of each position of the pattern element in the electrode pattern image is compared with the upper limit value and the lower limit value of the line width, and when the width of the position is larger than the upper limit value or smaller than the lower limit value, It is detected that a defect at the position has occurred. In this way, the entire width of all pattern elements in the electrode pattern image is compared with the upper limit value and lower limit value of the corresponding line width.

  When a defect is detected, for example, the electrode pattern image is displayed on the display unit 42 while making it possible to identify the defect position by surrounding it with a line of a predetermined color. The operator determines the presence or absence of abnormality in the resist stripping process of the resist stripping device 24 by confirming the type and number of defects displayed on the display unit 42, and if necessary, the pattern forming system 1 Stop the operation. If no defect is detected, a message to that effect is displayed. As described above, the comparison result between the electrode pattern image and the pattern image immediately after the etching is displayed on the display unit 42 and notified to the operator (step S26). The site of interest of the base material 9 is collected by the collection unit 112, and the process of forming a pattern for the site of interest is completed. The substrate 9 on which the transparent electrode pattern 921 is formed is used, for example, for manufacturing a capacitive touch panel.

  As described above, in the process monitoring device 4, a pattern image showing the photosensitive pattern 930 of the resist layer 93 after the exposure process for the resist layer 93 formed on the main surface of the substrate 9 and before the development process, A pattern image showing the resist pattern 931 after the development process, a pattern image showing the main surface after the etching process on the main surface on which the resist pattern 931 is formed and before the resist stripping process, and the main surface after the resist stripping process Pattern images indicating the transparent electrode pattern 921 are respectively acquired by the image acquisition units 3a to 3d.

  Here, the process of the comparative example which compares not only the photosensitive pattern image acquired by the image acquisition part 3a but the pattern image acquired by the image acquisition parts 3b-3d with design data is assumed. At the time when the photosensitive pattern image is acquired by the image acquisition unit 3a for each part of the substrate 9, only the exposure process by the exposure device 21 is performed, and the pattern of the photosensitive pattern 930 and the mask unit 211 This difference does not occur in principle. Therefore, in the comparison between the photosensitive pattern image and the design data, a certain area is detected as a defect even though it is not a defect, that is, detection of a false defect is suppressed. However, after the exposure process is completed, as the other processes (development process, etching process, and resist stripping process) are performed, the deformation (stretching / shrinking) of the film-like substrate 9 is accumulated. Therefore, when each of the pattern images acquired by the image acquisition units 3b to 3d is compared with the design data, many false defects are detected, and the occurrence of abnormality in the development process, the etching process, and the resist stripping process is accurately detected. It cannot be detected.

  On the other hand, the defect detection unit 41 of the process monitoring device 4 compares the two pattern images acquired immediately before and after the process for each of the development process, the etching process, and the resist stripping process, thereby The defect caused by is detected. Thereby, the detection of the false defect of the various patterns in the easily deformable film-like substrate 9 can be suppressed, and the occurrence of abnormality in each process can be accurately detected. Thus, by performing in-line process monitoring in photolithography, the quality of the transparent electrode pattern 921 formed on the substrate 9 can be stabilized, and the production yield can be improved.

  In the pattern forming system 1, the exposure process, the development process, the etching process, and the resist stripping process are continuously performed on the respective portions in the longitudinal direction of the belt-like substrate 9, that is, the substrate 9 is in a roll shape. Are sequentially performed while being drawn out without being wound around. Thereby, the pattern by an etching can be efficiently formed in the film-like base material 9.

  Here, in the pattern forming system 1, processing of another comparative example that acquires an image of a pattern only after the resist stripping process is assumed. In the process of the other comparative example, even if a defect due to an abnormality in the first half process occurs, the occurrence of the defect (an abnormality in the process) is not detected until an electrode pattern image is acquired after the resist stripping process. At this point, the process has been completed for many parts of the substrate 9, and a lot of waste is generated. It is also difficult to identify the process in which an abnormality has occurred.

  On the other hand, in the pattern forming system 1 that acquires a pattern image immediately after each of the exposure process, the development process, the etching process, and the resist stripping process, even if a defect due to an abnormality in the first half process occurs. The abnormality of the process can be detected at an early stage, and waste can be suppressed. In addition, the process in which an abnormality has occurred can be easily identified, and the pattern forming system 1 can be quickly recovered.

  In the defect detection unit 41, the pattern image immediately after etching to be compared with the electrode pattern image is compared with the resist pattern image. The resist pattern image is compared with the photosensitive pattern image, and the photosensitive pattern image is compared with the design data. Therefore, it can be said that the comparative inspection between the transparent electrode pattern 921 and the design data pattern is substantially performed in accordance with the deformation of the base material 9 (considering the deformation of the base material 9).

  In the image acquisition unit 3a, the resist layer 93 on the base material 9 that is formed of a photoresist and partially modified by exposure light exposure is taken as an imaging target. Then, the irradiation angle of the light irradiation unit 31 and the detection angle of the line sensor 32 are set to a predetermined setting angle, have a transparency to the resist layer 93 and are not included in the photosensitive wavelength band of the resist layer 93. The resist layer 93 is imaged by emitting the light from the light irradiation unit 31. As a result, an exposed portion of the resist layer 93, that is, an image showing the photosensitive pattern 930 can be appropriately acquired without affecting the non-photosensitive portion. As a result, it is possible to determine at an early stage whether there is an abnormality in the exposure process.

  The image acquisition unit 3a may be used separately from the pattern forming system 1 as an image acquisition device. For example, in the image acquisition device 30 illustrated in FIG. 10, the stage 110 a that is a support unit that supports the plate-like base material 9 a and the base material 9 a relative to the imaging region 90 in a direction intersecting the imaging region 90. A moving mechanism 11a is provided to move to.

  FIG. 11 is a cross-sectional view showing the substrate 9a. The base material 9a is a transparent member formed of glass, and an optical waveguide layer 94 is provided therein. The optical waveguide layer 94 is a layer on the surface of the base material 9a itself. By adding another material by doping (for example, ion implantation), a part of the layer 94 is altered to form a core 941 of the optical waveguide. Is done. The base material 9a is used as an optical waveguide device.

  The image acquisition device 30 performs processing according to the image acquisition processing of FIG. Specifically, the set angles of the irradiation angle θ1 and the detection angle θ2 that can increase the contrast of the core 941 of the optical waveguide in the captured image are obtained (step S121). Here, the contrast of the core 941 is the ratio of the gradation difference (absolute value) between the core 941 and the background area (cladding) in the captured image to the entire gradation range. The set angle at which the contrast of the core 941 becomes high is obtained by obtaining a captured image of the core 941 by a predetermined calculation or while changing the irradiation angle θ1 and the detection angle θ2.

  When the set angle is obtained, the irradiation angle θ1 and the detection angle θ2 are set to the set angle by controlling the angle changing mechanism 33 (step S122). Subsequently, emission of light from the light irradiation unit 31 is started, and the base material 9a is continuously moved in the lateral direction of FIG. 10 by the moving mechanism 11a. In parallel with the movement of the base material 9a, the line sensor 32 repeatedly acquires the line image of the linear imaging region 90 at high speed. Thereby, a two-dimensional captured image showing the core 941 of the layer 94 of the optical waveguide is acquired (step S123).

  In the image acquisition device 30 (image acquisition unit 3a), when a transparent layer is formed on the base material with another material different from the base material, and a part of the layer is altered by doping, the An image showing the altered portion of the layer may be acquired. Further, when the substrate itself is a photosensitive resin sheet or the like, an image immediately after exposure of the layer that is the entire substrate may be acquired. As described above, in the image acquisition device, a layer formed of another material on the base material, or a layer including the surface of the base material itself is used as a target layer, and a part thereof has been altered by a predetermined process. It is possible to appropriately acquire an image showing the altered portion in the target layer.

  The image acquisition apparatus (image acquisition unit) can be variously modified.

  The wavelength of the light emitted from the light irradiation unit 31 is not limited to a single wavelength, and light having a plurality of wavelengths may be selectively emitted. The light source may be provided with an LD instead of the LED. Further, a combination of a lamp such as a halogen lamp and a filter may be provided as the light source. The angle changing mechanism may be a mechanism that changes the irradiation angle and the detection angle in conjunction with each other.

  The configurations in the above-described embodiments and modifications may be combined as appropriate as long as they do not contradict each other.

3, 3a to 3d Image acquisition unit 9, 9a Base material 11 Conveyance mechanism 11a Movement mechanism 30 Image acquisition device 31 Light irradiation unit 32 Line sensor 33 Angle change mechanism 90 Imaging region 93 Resist layer 94 Optical waveguide layer 110 Conveyance roller 110a Stage 930 Photosensitive pattern 941 Core θ1 Irradiation angle θ2 Detection angle J1 Optical axis of light irradiation unit J2 Optical axis of line sensor N Normal of substrate S11 to S26, S121 to S123 Steps

Claims (8)

An image acquisition device,
A support unit for supporting the base material in which a part of the target layer has been altered by a predetermined treatment, with a layer formed of another material on the base material or a layer including the surface of the base material itself as the target layer When,
A light irradiation unit that emits light of a wavelength having transparency to the target layer;
A line sensor that receives light from a linear imaging region irradiated with the light;
A moving mechanism for moving the base material relative to the imaging region in a direction intersecting the imaging region;
An irradiation angle formed by the optical axis extending from the light irradiation unit to the imaging region and the normal line of the target layer, and a detection angle formed by the optical axis extending from the imaging region to the line sensor and the normal line are kept equal. And an angle changing mechanism for changing the irradiation angle and the detection angle,
An image acquisition apparatus comprising: The image acquisition device according to claim 1,
The target layer is a layer formed of a photosensitive material, and the part of the target layer is altered by light irradiation,
The image acquisition apparatus, wherein a wavelength of light emitted from the light irradiation unit is not included in a photosensitive wavelength band of the photosensitive material. The image acquisition device according to claim 2,
The image acquisition apparatus, wherein the target layer is a layer formed of a photoresist on the base material. The image acquisition device according to claim 1,
The image acquisition device, wherein the target layer is a layer of an optical waveguide provided on the base material itself, and the part of the target layer is altered by addition of another material by doping. An image acquisition method,
The base material in which a part of the target layer is altered by a predetermined treatment is prepared using a layer formed of another material on the base material or a layer including the surface of the base material itself as a target layer. A step of obtaining a set angle of an irradiation angle formed by a normal line of the target layer and an optical axis from a light irradiation unit that emits light having a wavelength having transparency to the target layer to a linear imaging region;
Setting the irradiation angle to the set angle, and setting a detection angle formed by an optical axis extending from the imaging region to a line sensor and the normal to the set angle;
Moving the substrate relative to the imaging region in a direction intersecting the imaging region to obtain an image;
An image acquisition method comprising: The image acquisition method according to claim 5,
The target layer is a layer formed of a photosensitive material, and the part of the target layer is altered by light irradiation,
The image acquisition method, wherein a wavelength of light emitted from the light irradiation unit is not included in a photosensitive wavelength band of the photosensitive material. The image acquisition method according to claim 6,
The image acquisition method, wherein the target layer is a layer formed of a photoresist on the base material. The image acquisition method according to claim 5,
The image acquisition method, wherein the target layer is a layer of an optical waveguide provided on the base material itself, and the part of the target layer is altered by addition of another material by doping.