JP2008209295A - Device for measuring size - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for measuring size of a multi-imaging head type, capable of performing stable size measurement by automatically performing matching parameters, including offset of measured values (each optical system) for each head, when creating a recipe. <P>SOLUTION: The device for measuring size of the multi-imaging head time with a plurality of imaging heads that is provided with an optical microscope includes recipe creation parts 20, 24 for creating measurement recipes for each imaging head by optimizing the parameters, including the offset value of the measured values due to each imaging head so that the measured values of patterns measured, based on image signals obtained by being imaged with the optical microscope of each imaging head, by using the same specimen to be measured are the same between the imaging head. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dimension measuring apparatus for measuring or inspecting a line width or a dimension by image processing, and more particularly to a dimension measuring apparatus of a multi-imaging head type.

  A dimension measuring apparatus that measures or inspects a dimension such as a line width performs a dimension measurement such as a pattern width or pattern interval of a TFT (Thin Film Transistor) of a substrate (for example, an LCD (Liquid Crystal Display) substrate) or a semiconductor mask. Device. The dimension measuring apparatus has a microscope and a camera (referred to herein as an imaging head or a microscope camera) for enlarging an image of a sample to be measured, and is formed on, for example, a transparent glass substrate (sample). The pattern image obtained by illuminating the pattern is magnified with a microscope, and the image is captured with a camera. The dimension measuring apparatus performs image processing on the obtained pattern image, and measures or inspects dimensions and shapes.

  Japanese Unexamined Patent Publication No. 2006-78303 (Patent Document 1) is known as a conventional dimension measuring apparatus. Patent Document 1 describes a multi-imaging head type dimension measuring apparatus that shortens the measurement time required to simultaneously measure a plurality of measurement objects.

JP 2006-78303 A

  However, in the above-mentioned Patent Document 1, in the multi-imaging head type dimension measuring apparatus, consideration is given to the case where some control parameters depending on the difference of the imaging head for each imaging head (optical system) are set as a measurement recipe. There wasn't. Here, the control parameters mean, for example, parameters related to drive control and autofocus control of the XY stage and parameters used for image processing.

  In view of the above problems, an object of the present invention is to provide a multi-imaging head type dimension measuring apparatus capable of automatically setting control parameters for each imaging head (for each optical system) at the time of creating a recipe. is there.

  In order to achieve the above object, the present invention provides a multi-imaging head comprising a plurality of microscope camera heads (imaging heads) for imaging a film-forming pattern formed on a sample to be measured when creating a recipe for measurement. Dimension measuring device of the method, using the pattern formed on the sample substrate to be measured, the measured value of the pattern measured based on the image signal obtained by imaging with the microscope camera of each imaging head, It is characterized in that a recipe creation unit is provided that can set control parameters for each imaging head so that they are substantially the same between the imaging heads regardless of differences between the imaging heads.

  Further, the present invention is a recipe creation method in a multi-imaging head type dimension measuring apparatus having a plurality of imaging heads equipped with a microscope camera for imaging a pattern formed on a measured sample, which is formed on the measured sample. A plurality of first measured values of the dimensions of the pattern based on a plurality of first image signals obtained by repeatedly imaging the film pattern with a microscope camera of the first imaging head a plurality of times, It is confirmed whether the reproducibility and measurement error of the aggregated first aggregated value are within the specified value, and if within the specified value, an average value is calculated from the plurality of first measured values and used as a reference value A plurality of dimensions of the pattern based on a reference value creating process and a plurality of second image signals obtained by repeatedly imaging the same pattern as the sample to be measured with a microscope camera of a second imaging head a plurality of times. The second measurement values are aggregated, and it is confirmed whether reproducibility and measurement error are within specified values in the aggregated second aggregated values. If the measured values are within the specified values, the plurality of second measured values are An average value is calculated, a difference between the calculated average value of the plurality of second measurement values and the reference value is calculated, and the calculated difference is calculated based on the first imaging head. And a recipe creating process that is set as an offset value for the imaging head.

  Furthermore, the dimension measuring apparatus of the present invention includes a plurality of imaging heads, and includes a recipe creating unit for measuring the dimensions of the pattern formed on the sample to be measured. Based on the created recipe, In the dimension measuring apparatus for measuring the dimension of the pattern formed on the sample to be measured from an image signal obtained by imaging with any one of the imaging heads, the recipe unit includes the plurality of the measurement areas of the same sample to be measured. Measure the dimensions based on the image signals obtained by imaging with the imaging heads, and change the control parameters of each imaging head so that the measured pattern dimensions are the same between the imaging heads. It is characterized by creating.

  According to the present invention, measurement errors and reproducibility due to differences in imaging heads (optical systems) during recipe creation are reduced, so that stable dimension measurement can be performed.

  Embodiments of a multi-imaging head type dimension measuring apparatus according to the present invention will be described with reference to the drawings.

  First, a schematic configuration of a multi-imaging head type dimension measuring apparatus when an LCD (Liquid Crystal 1 Display) substrate or the like according to the present invention is used as a sample to be measured will be described with reference to FIG. FIG. 1 schematically shows a schematic configuration of a multi-imaging head type dimension measuring apparatus, which is an example provided with two imaging heads.

  That is, the microscope in each of the imaging heads 50a and 50b includes straight tubes 3a and 3b, light projecting tubes 4a and 4b, revolvers 5a and 5b, and objective lenses 6a and 6b.

  In the description of FIG. 1, the suffixes a and b of the suffix indicate that they belong to the imaging head 50a or the imaging head 50b, respectively. Hereinafter, although the embodiment will be described with the imaging head 50a, the imaging head 50b operates in the same manner unless otherwise specified.

  The measurement camera 1a in the imaging head 50a captures an image of the sample to be measured magnified by a microscope, inputs the image to the overall control unit 20, and stores the image in, for example, the image memory 20-1. The camera 1a is, for example, a CCTV (Closed Circuit Tele-Vision) camera. The sample is used to set a part of the parameters depending on the difference of the imaging head (optical system) for each imaging head for each imaging head when creating a measurement recipe in the present invention. And the pattern for measurement selected by the recipe creator. Usually, one sample is selected for one type of sample to be measured (for example, the pattern of the same layer of the LCD substrate). Also, this sample is often selected from a plurality of patterns that actually require dimension measurement.

  The automatic dimming adapter 2a of the imaging head 50a is based on a command from the overall control unit 20 so that the amount of light (amount of received light) reaching the imaging element (for example, a CCD (Charge Coupled Device)) of the camera 1a becomes a specified value. Is adjusted by the light control unit 26a. For example, the overall control unit 20 obtains the maximum value of the luminance level of the acquired sample image signal, and controls the automatic light adjustment adapter 2a so that the maximum value becomes a predetermined value.

  The light output from the exit of the reflection illumination light source unit 9a of the microscope passes through the light guide 7a of the imaging head 50a, the light projecting tube 4a, the half mirror (not shown) in the straight tube 3a, and the objective lens 6a, and on the sample table 8. The sample (sample to be measured) is irradiated. The light guide 7a is made of, for example, an optical fiber.

  The sample to be measured on the sample stage 8 reflects the irradiated light, and the reflected light passes through the objective lens 6a, the straight tube 3a, and the automatic light adjustment adapter 2a, reaches the imaging surface of the camera 1a, and is captured as a subject image. The image signal converted into the electrical signal is output to the overall control unit 20.

  The microscope unit in the imaging head 50a is attached to the Z stage 10a of the imaging head 50a, and is driven by the motor 11a based on the control from the autofocus control unit 27a. Can be adjusted to the surface of each sample to be measured.

  When adjusting the in-focus position, for example, a commercially available laser focus device using a knife edge is used as the tracking autofocus units 12a and 12b. In the laser focus device, a detector (for example, PSD (Position Sensitive Detector)) for detecting the focus position needs to be attached to each imaging head. Since this mounting position is slightly different between the respective imaging heads (imaging heads 50a and 50b), a difference occurs in the adjusted in-focus position for each imaging head. That is, by setting the parameter PLS for setting the position of the detector separately for each imaging head, it is possible to reduce the difference in focal position between the imaging heads.

  The tracking type autofocus unit 12a of the imaging head 50a is a reflection detected from the surface of the sample to be measured even while the sample to be measured (substrate) is moving in the XY direction relative to the imaging head 50a. The Z stage 10a is controlled so that the contrast of the optical image is maximized, and the focus position of the microscope is always adjusted to the surface of the sample to be measured. For example, the overall control unit 20 obtains the maximum value and the minimum value of the luminance level of the acquired image signal, and the Z stage so that the difference between the maximum value and the minimum value becomes a predetermined value (contrast becomes a predetermined value). 10a is controlled.

  That is, the multi-imaging head type dimension measuring apparatus according to the present invention is configured by mounting a plurality of imaging heads. In the embodiment of FIG. 1, the configuration in which the reflection illumination light source units 9a and 9b are separately provided is shown, but they can be shared. Further, between the sample stage 8 and each imaging head, an XY movement mechanism (not shown) is driven by the control of the mechanism control unit 28 based on a command from the overall control unit 20 to relatively XY. It is configured to be movable in the direction.

  As described above, all parameters necessary for measurement are created in the recipe creation unit 20-3 using the processing terminal 24 and the like, stored in the storage device 25, and used when measurement is performed.

  The main purpose of the multi-imaging head configuration is to shorten the inspection tact time. Therefore, the overall control unit 20, a display device (processing terminal) 24 including a GUI (Graphical User Interface) connected to the overall control unit 20 and input means, and the storage device 25 are shared by the multi-imaging head, and further mechanism control is performed. The unit 28 is also configured to be shared by multiple imaging heads. The overall control unit 20 mainly includes an image memory 20-1, a CPU (Central Processing Unit) functionally provided with an image processing control unit 20-2 and a recipe creation unit 20-3. Therefore, since a plurality of imaging heads function independently and can be moved to different measurement locations, the measurement location of the sample to be measured can be measured by the number of imaging heads at a time, thereby reducing the inspection tact time. it can.

  Next, as described above, after setting the parameter PLS of the position of the autofocus detector for each imaging head so that the contrast becomes a predetermined value, the offset value for each imaging head is set. An example of setting an offset value for each imaging head will be described with reference to FIGS.

  First, a processing operation in which, for example, the image processing control unit 20-2 measures a dimension such as a line width using sample images captured by the measurement cameras 1a and 1b of the imaging heads 50a and 50b will be described with reference to FIG. FIG. 2 is a diagram showing a part of the pattern formed on the sample to be measured.

  In the description of FIG. 2, the reference numbers suffix a and b indicate that they belong to the imaging head 50a or the imaging head 50b, respectively. Hereinafter, although the embodiment will be described with the imaging head 50a, the imaging head 50b operates in the same manner unless otherwise specified.

  A pattern 31 is measured by the imaging head 50a in order to determine a control parameter including an offset value for each imaging head. Reference numeral 32 is a reference pattern for detecting the reference position of the sample to be measured by pattern matching, and 34 is a frame indicating the registered position range of the reference pattern 32. Reference numerals 33-1 and 33-2 are frames indicating measurement areas captured by the camera 1 a based on the detection position of the reference pattern 32. Reference numeral 35 denotes a scanning line. When the horizontal axis is a position on the scanning line 35, 33-1D is the left end of the measurement area 33-1, 33-1U is the right end of the measurement area 33-1, and 33-1H. Is the edge of the pattern 31 in the measurement area 33-1, 33-2U is the left end of the measurement area 33-2, 33-2D is the right end of the measurement area 33-2, and 33-2H is the pattern 31 in the measurement area 33-2. Is the edge. The measurement areas 33-1 and 33-2 are set at positions where the edge of the pattern on the sample to be measured can be recognized. The edge position is, for example, the position of the intermediate value (50%) of the difference between the maximum value and the minimum value of the luminance detected on the scanning line 35 in the measurement area 33-1 or 33-2.

  That is, the position coordinates of the measurement areas 33-1 and 33-2 are relatively calculated based on the registration position of the reference pattern 32. Therefore, for example, the image processing control unit 20-2 can measure the dimension L between both edges in the two measurement areas by calculating the edge positions in the measurement areas 33-1 and 33-2. .

  As described above, all parameters necessary for measurement for each imaging head are also created in the recipe creation unit 20-3 using the processing terminal 24 and the like, stored in the storage device 25, and used when measurement is performed. The

  Next, an example of a process for measuring the line width of the pattern 31 and a process for determining an offset value from the image signals acquired from the measurement areas 33-1 and 33-2 described in FIG. 2 will be described with reference to FIG. . FIG. 3 is a diagram showing the relationship between the cross-sectional view of the pattern 31 and the luminance waveform of the image signal in the measurement areas 33-1 and 33-2 on the scanning line 35 (see FIG. 2) of the pattern 31. FIG. The horizontal axis is the position of the scanning line 35 (horizontal axis direction in FIG. 2).

  FIG. 3A is a partial cross-sectional view of the sample to be measured at the scanning line 35. The horizontal axis indicates the position on the scanning line 35 in FIG. 2, and the vertical axis indicates the thickness of the pattern formed on the LCD substrate. Indicates direction. 3B is a luminance waveform of an image signal acquired by the imaging head 50a for the sample to be measured of FIG. 3A, and FIG. 3C is a sample to be measured (FIG. 3B and FIG. 3B). The luminance waveform of the image signal acquired with the imaging head 50b about the same thing) is shown. The horizontal axes in FIGS. 3A and 3B are synchronized with the horizontal axis in FIG. 3A, indicate the position on the scanning line 35 in FIG. 2, and the vertical axis indicates the luminance level.

  In FIG. 3A, 40 is a glass substrate, 40-1 is the surface (upper surface) of the glass substrate 40, and 31 is a pattern formed on the glass substrate 40. The vertical line 43-1D is the position of the left end (black dot) A of the pattern 31 and indicates the same position in FIGS. 3B and 3C. Similarly, the vertical line 43-1U is the position of the left edge end (black dot) b of the pattern 31 and indicates the same position in FIGS. 3B and 3C. A vertical line 43-2D is the position of the right end (black dot) d of the pattern 31 and indicates the same position in FIGS. 3B and 3C. Similarly, the vertical line 43-2U is the position of the right edge end (black dot) c of the pattern 31 and indicates the same position in FIGS. 3B and 3C. In FIGS. 3B and 3C, only the luminance waveforms of the measurement areas 33-1 and 33-2 (see FIG. 2) are acquired (needed), but should be drawn with separate luminance waveforms. For convenience, the luminance waveform is shown continuously between the measurement areas 33-1 and 33-2.

  Moreover, the pattern 31 in FIG. 2 does not draw the edge part in detail. Actually, the edge portion is tapered as shown in FIG. Between sunspots and between sunspots honey. And when the line width L is the length of the pattern 31 on the glass substrate upper surface 40-1 (between black dots), the line width L is the length of the upper part of the pattern 31 (between black dots and lo), or In some cases, the length is between the tapered portions (for example, the length between the left and right circles in FIG. 3A). In the present embodiment, as will be described in the embodiment of FIG. 2, the length in the vicinity of the position of half the thickness of the pattern 31 (intermediate portion of the taper) is set as the line width L. That is, the line width L is measured as the distance between the vertical lines 43-1H and 43-2H from the luminance waveform 41a of the imaging head 50a.

  The measurement method is such that the minimum and maximum luminance values are obtained from the luminance waveform 41a of the measurement areas 33-1 and 33-2 (see FIG. 2) acquired from the imaging head 50a, and a predetermined slice level point (black dot home) is obtained. The length is calculated from the position coordinates, and the calculated length is obtained as the line width La (FIG. 3B). In this embodiment, the slice level is set to 50%, but may be changed according to the type of the sample to be measured.

  Next, when the measurement is performed using another imaging head instead of the imaging head 50a, the line width is different. That is, the minimum value and the maximum value of the luminance are obtained from the luminance waveform 42a of the same measurement areas 33-1 and 33-2 (see FIG. 2) acquired by the imaging head 50b. Then, the position coordinates (that is, the distance between the vertical line 43-1H 'and the vertical line 43-1H') between the points at a predetermined slice level (the circle mark between the black dot lines and the circle mark between the black dot lines). ) And the calculated length becomes the measured line width Lb (FIG. 3C).

  As shown in FIG. 3, the cross-sectional shape of the pattern 31 in FIG. 3A does not match the luminance waveforms 41a and 41b in FIGS. 3B and 3C as they are. That is, the positions of the horizontal axis in the scanning line direction are respectively the luminance waveforms 41a and 41b obtained by the imaging heads 50a and 50b with respect to the vertical lines 43-1D, 43-1U, 43-2D, and 43-2U, respectively. The black spots e, f, h, g, r, n, le, w, which indicate the end of the taper, are in different positions. Similarly, the positions of the circles indicating the slice levels of the luminance waveforms 41a and 41b are also different (vertical lines 43-1H, 43-1H ′, 43-2H, 43-2H ′). Therefore, in the embodiment of FIG. 3, the values (lengths) of the line widths L, La, and Lb are different (the ends of the vertical lines 43-1H and 43-1H ′ between FIGS. 3B and 3C). (Refer to the broken circle in the section.)

  As described above, when there are a plurality of imaging heads (two in this embodiment), even if the dimensions of the same pattern 31 are measured as shown in FIG. As shown in c), for each of the imaging heads 50a and 50b, for example, luminance waveforms 41a and 41b, a difference due to the different imaging heads occurs in the luminance level, and a difference in the dimension measurement value occurs. Therefore, the line width La measured by the imaging head 50a and the line width Lb measured by the imaging head 50b are not the same value. This is because the shape of the edge to be measured apparently changes due to differences in the optical axes of the imaging heads 50a and 50b, mechanical or electrical differences, and the like.

Accordingly, when the imaging head 50a used at the time of recipe creation is used as a reference (that is, the offset value of the imaging head 50a is set to zero), the offset value OF _b-a of the imaging head 50b is expressed by the following equation.

OF _b−a = Lb−La (1)
If there are n imaging heads, the line width Ln of the n-th imaging head 50n is measured as described above, and is calculated as follows using the imaging head 50a used when creating the recipe as a reference. (N is a natural number).

OF _n−a = Ln−La (2)
As described above, the recipe creation unit 20-3 sets an offset value depending on which of the imaging heads is used for measurement when creating a recipe. Thus, the measurement recipe can reduce the difference for each optical system by offsetting the measurement value according to the imaging head to be used. At this time, a parameter that must be adjusted for each optical system (for example, a parameter that corrects a change in the in-focus position due to a difference (error) in the installation position of a sensor (detector) that detects the in-focus position for each optical system) ) Is corrected. For example, the tracking type autofocus detection optical systems 12a and 12b described above must individually set parameters (parameters for correcting differences in in-focus positions between the tracking type autofocus detection optical systems).

  As described above, in the multi-imaging head type dimension measuring apparatus according to the present invention, an offset value is provided for each optical system (imaging head), and at the same time, together with some control parameters depending on the difference in the imaging head such as the optical system. Set as a measurement recipe.

  Next, an embodiment of recipe creation in the multi-imaging head type dimension measuring apparatus according to the present invention will be described with reference to FIG.

  In FIG. 4, the recipe creator starts an operation of creating a recipe for the sample to be measured (substrate) on the sample stage 8 (see FIG. 1) of the measuring apparatus. Thus, first, the recipe creating unit 20-3 displays design information such as an LCD substrate on the display screen of the processing terminal 24, and executes each step described in FIG. The recipe creator selects an arbitrary position in the substrate, selects the pattern 31 as shown in FIG. 2, and uses the processing terminal 24 to select necessary items such as the measurement areas 33-1 and 33-2 and the scanning line 35. Set (pattern selection step S41).

  Next, one arbitrary optical system (imaging head) is selected on the display screen of the processing terminal 24. The imaging head selected first becomes the reference imaging head used in the remaining recipe creation step (S49) described later, but can be changed later. For example, when the imaging head 50a is selected, the imaging head 50a becomes the reference imaging head (imaging head selection step S42).

  Next, control parameters other than the offset value are set for the selected imaging head (for example, imaging head 50a) (control parameter setting step S42). The control parameter is, for example, the above-described parameter PLS of the position of the autofocus detector.

  Next, it is determined whether or not the setting has been completed for all parameters, and if not completed, the control parameter setting step S42 is repeated, and if completed, the process proceeds to the next step (S44) (all parameter completion determination). Step S43).

  Next, the image processing control unit 20-2 measures the dimensions with the parameters set in step S42 using the selected imaging head (dimension measurement step S44).

  Next, in the measurement number determination step S45, it is determined whether or not the measurement number is within a specified number. If it is not the specified number, step S44 is executed again. If it is the specified number, the process proceeds to the next step (S46). (Measurement count determination step S45). The prescribed number of measurement times is set in advance and stored in the storage device 25, but may be newly created or changed at the time of recipe creation depending on the situation at the time of recipe creation. Further, the specified number of times of measurement may be different for each imaging head.

  Next, after the measurement (after completion of steps S44 and S45), the measured values of the pattern dimensions obtained from the image processing control unit 20-2 are aggregated (aggregation step S46). In addition, after executing step S44, the aggregation process (step S46) may be executed, and when the number of measurements reaches the specified number, the process of step S47 described later may be performed (determined).

  Next, it is determined whether or not reproducibility and measurement error are within specified values. If it is within the specified value, the average value of the measured values is stored in the storage device 25 as a reference value (reproducibility determination step S47). If the current imaging head is the imaging head first designated when creating this recipe, that is, the reference imaging head, it is first determined whether or not the number of measurement errors is equal to or greater than the specified number. When it is determined that the measurement error is equal to or greater than the specified number of times, the recipe creation process is terminated. When the processing is completed, a character display or a graphic symbol display indicating that the recipe creation has been completed is performed on the display screen of the processing terminal 24. If there is a sound or generating means, a sound indicating the end is output. Furthermore, information on the occurrence of measurement errors (type of imaging head, number of measurement errors, etc.) is displayed.

  When the measurement error is not equal to or greater than the specified number (less than the specified number), the reproducibility is determined next. For determination of reproducibility, for example, an average value of dimensions measured for each imaging head is obtained. Further, a standard deviation is calculated. In the case of a reference imaging head, the average value and the standard deviation are obtained and stored. In the case of an imaging head other than the reference, an average value is calculated, and if the calculated average value is within the standard deviation of the average value calculated by the reference imaging head, for example, is within a specified value (with reproducibility) ) And the process proceeds to step S48.

  In the above embodiment, it is determined that there is reproducibility if the average value of the other imaging head is within the standard deviation of the average value Ave of the reference imaging head. However, instead of the standard deviation, a separately determined value α is used. , Ave (average value of the reference imaging head) plus or minus α (separately determined value) may be used as the specified value range with reproducibility. The value α may be a value related to the accuracy of the measuring apparatus. Furthermore, when the line width of the pattern to be measured is a predetermined value LL, LL plus or minus α may be used.

  Note that the reproducibility determination (step S47) after the aggregation process may be performed every time the dimension measurement (S44) is performed, as in the aggregation (S46).

Next, in step S48, an offset value is calculated. When the imaging head is the reference imaging head, the offset value is set to zero, and when the imaging head is another imaging head, the calculation of Expression (2) is performed from the average value La of the dimensions aggregated by the reference imaging head and the average value Ln of each imaging head. To calculate the offset value OF _b-a .

  In step S49, the calculated offset value and the set parameter are reflected in the recipe. For example, the recipe is stored in the storage device 50, but may be temporarily stored in the recipe creating unit 20-3.

  Next, in step S50, it is determined whether there is an imaging head that has not yet performed the processes of S41 to S49. If there is another optical system (imaging head), the process returns to step S42, and in the same measurement area of the same pattern selected in the pattern selection step S41 by the other optical system (imaging head) based on a command from the overall control unit 20. Processing of repeated steps S42 to S48 is performed. At this time, before returning to S42, the overall control unit 20 instructs the mechanism control unit 28 so that the same pattern can be imaged by a measurement camera (for example, the camera 1b) attached to another optical system (imaging head). And an XY movement mechanism (not shown) is driven to move the sample automatically.

  As described above, the same operation is repeated for the number of optical systems.

  If it is determined in step S50 that there is no imaging head that has not yet performed the processes in steps S41 to S49, the process proceeds to step S51.

  In step S51, conventional recipe creation is continued, such as setting all measurement points on one substrate (sample to be measured), mainly using a reference imaging head, and recipe creation is terminated.

  In this way, the recipe creation unit 20-3 sets the offset and some parameters that differ for each imaging head as measurement recipes and stores them in the storage device 25 for each imaging head. As a result, the burden on the operator can be reduced and, at the same time, the dimension of the pattern can be measured using the optimum measurement recipe for each imaging head, so that stable dimension measurement is possible.

  The configuration of the dimension measuring apparatus according to one embodiment of the present invention will be described with reference to FIG. FIG. 5 is a diagram for explaining the configuration of a two-head LCD (Liquid Crystal Display) dimension measuring apparatus using the present invention. 5A is a plan view of the apparatus viewed from above, FIG. 5B is a plan view of FIG. 5A viewed from the direction of arrow A, and FIG. It is the figure which looked at the top view of a) from the direction of arrow B.

  With reference to FIG. 5, the configuration and operation direction of the moving shaft of the two-head LCD dimension measuring device will be described. Reference numeral 101 denotes a pedestal, 103 denotes a sample to be measured, and 102 denotes a sample table on which the sample to be measured 103 is mounted. A sample stage 102 is fixed on the pedestal 101, and the sample 103 to be measured is carried in or out on the sample stage 102 by a transport unit (not shown). The sample to be measured 103 carried in from the transport unit is fixed to the sample stage 102 by a method such as vacuum suction. For example, the sample 103 to be measured is adsorbed by an adsorption mechanism (not shown) of a two-head LCD dimension device and fixed to the sample stage 102. The sample 103 to be measured is, for example, a plate-like substrate such as a substrate, and measures or inspects dimensions such as a line width of a film pattern formed or applied on the plate-like substrate. The plate-like substrate is, for example, a TFT (Thin Film Transistor) of an LCD (Liquid Crystal Display) substrate or a semiconductor mask.

  The two-head LCD dimension measuring device is a dimension measuring device including two imaging head units, and the N-head LCD dimension measuring device is a dimension measuring device including N imaging head units (N is 2). More natural numbers).

  Reference numeral 501 denotes a Y-axis beam, 502 denotes an X1-axis guide, and 503 denotes an X2-axis guide. The Y-axis beam 501 moves on the X1-axis guide 502 and along the X2-axis guide 503 in parallel to the X-axis (in FIG. 5A, the left-right direction on the paper surface). The rail portion of the Y-axis beam 501 (hereinafter referred to as the Y-axis rail) is configured to be orthogonal to the X-axis. Alternatively, the height of the X1-axis guide 502 and the X2-axis guide 503 may be lowered, and the Y-axis beam 501 may have a gate type (gantry) structure.

  Reference numeral 504 denotes a Y1-axis guide, and reference numeral 505 denotes a Y2-axis guide. The Y1-axis guide 504 and the Y2-axis guide 505 move independently along the Y-axis rail. At this time, the Y1-axis guide and the Y2-axis guide move in the direction perpendicular to the X axis (the Y axis (the vertical direction in FIG. 5A)).

  Reference numeral 506 denotes a Z1-axis guide, and reference numeral 507 denotes a Z2-axis guide. The Z1-axis guide 506 is mounted on the Y1-axis guide 504, and the Z2-axis guide 507 is mounted on the Y2-axis guide 505. The Z1-axis guide 506 moves along the Y1-axis guide 504 in the Z-axis direction (the vertical direction in FIG. 5B). Similarly, the Z2-axis guide 507 is changed to the Y2-axis guide 505. Along the Z axis.

  Reference numeral 508 denotes a ΔX1 axis guide, 509 denotes a ΔX2 axis guide, and 510 and 511 denote imaging head units. The ΔX1-axis guide 508 is mounted on the Z1-axis guide 506, and the ΔX2-axis 509 guide is mounted on the Z2-axis guide 507.

  The imaging head unit 510 is mounted on a ΔX1-axis guide 508, and the imaging head unit 511 is mounted on a ΔX2-axis guide 509.

  The imaging head unit 510 moves in the X-axis direction along the ΔX1-axis guide 508. Similarly, the imaging head unit 511 moves in the X-axis direction along the ΔX2-axis guide 509.

  Further, in the embodiment of FIG. 5, a transmission illumination shaft mechanism that operates in pairs with the imaging head portions 510 and 511 is provided. That is, 512 is the Py1 axis of the imaging head unit 510, 513 is the Py2 axis, 514 is the ΔPx1 axis, and 515 is the ΔPx2 axis.

  The Py1 axis 512 and the Py2 axis 513 are mounted on the transmitted illumination guide 104 suspended from the Y-axis beam 501 and operate along the transmitted illumination guide 104 in the Z-axis direction.

  Further, a ΔPx1 axis 514 is provided on the Py1 axis 512, and a ΔPx2 axis 515 is provided on the Py2 axis 513. A transmission illumination 516 is mounted on the ΔPx1 axis 514, and a transmission illumination 517 is mounted on the ΔPx2 axis 515.

  The transmitted illumination 516 moves in the X axis direction along the ΔPx1 axis 514, and similarly, the transmitted illumination 517 moves in the X axis direction along the ΔPx2 axis 515.

  The movement of the transmitted illumination 516 along the ΔPx1 axis 514 and the movement of the imaging head unit 510 along the ΔX1 axis 508 are interlocked. For example, the emission center axis of the illumination light of the transmitted illumination 516 and the imaging head The incident optical axis of the unit 510 is the same optical axis 111.

  Similarly, the movement of the transmission illumination 517 along the ΔPx2 axis 515 and the movement of the imaging head unit 511 along the ΔX2 axis 509 are interlocked. The incident optical axis of the imaging head unit 511 is the same optical axis 112.

  5B, a part of the beam 501, the Py1 axis 512, the Py2 axis 513, the ΔPx1 axis 514, the ΔPx2 axis 515, the transmitted illuminations 516 and 517 attached to the beam 501, and the sample table 102 is a view that is easy to see by mixing a portion that can be seen from the direction of arrow B and a portion that cannot be seen, and is not an accurate side view. Similarly, FIG. 5C is a schematic cross-sectional view.

1 is a schematic diagram showing an embodiment of a multi-imaging head type dimension measuring apparatus according to the present invention. It is explanatory drawing of the dimension measurement by the multi-imaging head type dimension measuring apparatus which concerns on this invention. It is a figure for demonstrating one Example of the cross-sectional view of the pattern which concerns on this invention, and the relationship between the luminance waveform of the image signal of a measurement area. It is a flowchart which shows one Embodiment of the preparation procedure of the measurement recipe in the multi-imaging head type dimension measuring apparatus which concerns on this invention. It is a figure for demonstrating the structure of the dimension measuring apparatus of the 2 head system which concerns on this invention.

Explanation of symbols

  la, 1b ... camera, 2a, 2b ... automatic light control unit, 3a, 3b ... straight tube, 4a, 4b ... floodlight, 5a, 5b ... revolver, 6a, 6b ... objective lens, 7a, 7b ... light guide, 8 ... Sample stage, 9a, 9b ... Reflective illumination light source unit, 10a, 10b ... Z stage, 11a, 11b ... Motor, 12a, 12b ... Tracking autofocus detection optical system, 20 ... Overall control unit, 20-1 ... Image memory 20-2: Image processing control unit, 20-3: Recipe creation unit, 24 ... Processing terminal (display device), 25 ... Storage device, 26a, 26b ... Dimming control unit, 27a, 27b ... Autofocus control unit, 28 ... mechanism control unit, 30 ... reference pattern, 32 ... reference pattern, 34 ... frame indicating reference image registration position range, 33-1, 33-2 ... measurement area, 33-1D ... measurement area 33-1 Left end, 33-1U ... right end of measurement area 33-1, 33-1H ... edge of pattern 31 in measurement area 33-1, 33-2U ... left end of measurement area 33-2, 33-2D ... measurement area 33- 2 right end, 33-2H: edge of pattern 31 in measurement area 33-2, 35: scanning line, 41a: imaging head 50a luminance waveform, 41b: imaging head 50b luminance waveform, 50a, 50b: imaging head.

Claims (1)

A plurality of imaging heads, a recipe creation unit for measuring the dimension of the pattern formed on the sample to be measured, and obtained by imaging with any of the plurality of imaging heads based on the created recipe In a dimension measuring apparatus for measuring a dimension of a pattern formed on the measurement sample from an image signal obtained,
The recipe unit measures dimensions based on image signals obtained by imaging the same measurement area of the same sample to be measured with the plurality of imaging heads, and the measured pattern dimensions are the same between the imaging heads. A dimension measuring apparatus that creates a recipe so that the control parameters of each imaging head are changed.

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