KR20100034039A - Micro-dimension measuring method and measuring device - Google Patents

Abstract

A conventional micro-dimension measuring device, if there are a plurality of similar or identical patterns on the measurement screen of an object to be measured, is likely to make measurement in similar or identical patterns other than a previously registered pattern. In a micro-dimension measuring method by which a predetermined portion of the object to be measured is enlarged and captured by a TV camera, and the dimension of the predetermined pattern is measured by an image processing from the image of the TV camera having captured it, a measurement reference window for detecting a search area having a predetermined size and the predetermined pattern in pattern matching is set on the image of the TV camera and the measurement reference window is properly moved within the search area having the predetermined size to detect the predetermined pattern.

Description

Micro-dimensional measurement method and measuring device {MICRO-DIMENSION MEASURING METHOD AND MEASURING DEVICE}

The present invention relates to a micro dimensional measuring method and a measuring apparatus, and more particularly, to a micro dimensional measuring method and measuring apparatus for measuring the dimensions and the like of a target in a non-contact by using a two-dimensional sensor.

BACKGROUND ART Micro-dimension measuring apparatuses have conventionally been known as micro-dimension measuring methods for measuring line widths such as fine wiring patterns formed on glass substrates such as semiconductor substrates and liquid crystal displays, for example, liquid crystal display (LCD) devices. As shown in FIG. 6, the micro-dimension measuring device uses the optical microscope 603 as a TV camera 604 to measure the surface of the measurement target 602 mounted on the sample stage 601, for example, the glass substrate of the LCD device. To the imaging unit 605. The spatial image of the surface of the projected object 602 is captured by the imaging unit 605 of the TV camera 604 and input to the dimension measurement arithmetic processing unit 606 as a video signal. In the dimension measurement arithmetic processing unit 606, the dimensions of the predetermined portion of the measurement target object 602 are electrically measured, and the image and the dimension measurement value of the measurement object 602 are displayed on the TV monitor 607. 608 denotes an input unit such as a mouse. The operation of the dimension measurement arithmetic processing unit 606 will be described with an operation flowchart shown in FIG. 8 described later.

Here, the method of measuring the line width of the wiring pattern of the to-be-measured object 602 etc. using the said micro dimensional measuring apparatus is demonstrated using FIG. First, FIG. 7A shows a monitor image 701 of the surface of the measurement object 602 taken by the TV camera 604. 702 denotes a horizontal scanning line for scanning the monitor image 701, and 703 denotes, for example, a wiring pattern on the surface of the measurement object 602. FIG. In addition, the wiring pattern 703 has a high reflectance of light and is bright, and a circumference of the wiring pattern 703 is low and dark. The same shall apply to the following drawings. Li represents the i-th horizontal scanning line, and the luminance distribution on this i-th horizontal scanning line is shown in FIG. That is, Fig. 7B shows luminance-pixel characteristics, the horizontal axis represents the number N of pixels in the horizontal direction of the monitor image 701, and the vertical axis represents the luminance level.

As a measuring principle of the wiring pattern 703, dimensions are obtained from the luminance-pixel characteristics. For example, the maximum luminance level 705 in the luminance distribution curve 704 of FIG. 7B is 100%, the minimum luminance level 706 is 0%, for example, the luminance level 707 of 50%. The positional difference Nab between the a-th pixel and the b-th pixel corresponding to is obtained. Subsequently, the position difference Nab corresponds to the measurement object corresponding to the coefficient k determined by the measurement magnification of the optical microscope 603 at this time and the object distance from the TV camera 604 to the measurement object 602 ( The dimension X of the wiring pattern 703 of 602 is obtained by the following equation (1).

X = k × Nab... (One)

Using this principle, the wiring pattern 703 of the object under test 602 is measured, and the method in that case will be described. As shown in Fig. 7C, first, the template registration window PW for pattern matching (the coordinate axis at the center thereof is (0,0). In the following description, the measurement reference window PW is abbreviated) and the designated area. Registration window LW (the coordinate axis of its center is referred to as (Lx, Ly). In the following description, measurement window LW is abbreviated.) And registration window RW (the coordinate axis of the center is referred to as (Rx, Ry)). In the following description, a method of registering the measurement window RW) will be described. In addition, a window (window) means the range of the rectangular shape shown by FIG.7 (c). The same applies to the following drawings. As shown in Fig. 7C, first, the measurement pattern window PW is picked up on the TV monitor 607 by imaging the wiring pattern of the measurement target (not shown), which is a known reference. Is dragged with the mouse 608 to select the measurement reference window PW, and the image within the measurement reference window range is registered as a pattern matching image. Next, the measurement window LW and the measurement window RW are dragged with the mouse 608, respectively, and the position of the line width to be measured is selected, and this is registered as the measurement range. Thereby, the measurement reference window PW, the measurement window LW, and the measurement window RW are registered as a predetermined position as the to-be-measured object used as a known reference. That is, they are registered in the positional relationship as shown in Fig. 7C.

Subsequently, it replaces with the unknown to-be-measured object 602, image | photographs the wiring pattern of an unknown to-be-measured object with the TV camera 604, and searches the place which matches the wiring pattern of the measurement reference window PW registered previously. do.

Although this search method is performed in the dimension measurement arithmetic processing unit 606 using a conventionally well-known pattern matching method, detailed description is abbreviate | omitted here. By this pattern matching method, the position of the measurement reference window PW is detected from the wiring pattern 703 of the unknown object 602, and the measurement window LW and measurement window RW which have already been registered are determined based on this. Then, for example, the left contour is detected in the measurement window LW, and the right contour is detected in the measurement window RW, for example.

Each positional relationship at this time is registered as follows. That is, the center position of the measurement reference window PW is the (0,0) coordinate, the center position of the measurement window LW is the (Lx, Ly) coordinate, and the center position of the measurement window RW is the (Rx, Ry) coordinate. Register. The measurement target window PW is KWx and KWy, and the width of the measurement window LW is LWx, LWy, and the width of the measurement window RW is RWx and RWy. It is possible to measure the dimension of the line width at a predetermined position of the wiring pattern 703.

Here, the method of dimensional measurement is also described in detail. First, the maximum luminance and the minimum luminance within the ranges of the measurement window LW and the measurement window RW are determined, and the dimension measurement is performed by the above-described method. That is, the dimension measurement is first performed as a processing of the measurement window RW between a luminance level of 50% from a luminance level of 100% maximum brightness and 0% minimum brightness between Rx- (RWx / 2) and Rx + (RWx / 2). Decide The pixel position b having the luminance level of 50% is calculated and calculated by the dimension measurement arithmetic processing unit 606. Next, as the processing of the measurement window LW, the luminance level of 50% is determined from the luminance level of the maximum luminance of 100% and the minimum luminance of 0% between Lx- (LWx / 2) and Lx + (LWx / 2). Similarly, the pixel position a having the luminance level of 50% is calculated and calculated by the dimension measurement arithmetic processing unit 606. The difference (position difference Nab between pixels) of these pixel positions a and b is calculated | required, and to this position difference Nab, the to-be-measured object 602 from the measurement magnification of the optical microscope 603 at this time, and the TV camera 604. The predetermined dimension value X of the wiring pattern 703 of the measurement object 602 can be obtained from the coefficient k determined by the object distance up to).

By the way, in the micro-dimension measuring apparatus mentioned above, generally, the board | substrate or the optical microscope of a to-be-measured object is moved to a relatively XY-axis direction, and a target pattern is measured at the previously registered coordinate position. This will be described with reference to FIGS. 8 and 9. 8 is a diagram illustrating a flowchart for explaining the operation of the conventional micro-dimension measuring apparatus. 9 shows a measurement screen in which a predetermined portion of the measurement object 602 is enlarged by the optical microscope 603 and the image captured by the TV camera 604 is displayed on the TV monitor 607. This measurement screen is 10 micrometers x 10 micrometers, for example.

In FIG. 8, first, measurement is started in step 801. In step 802, the object 602 is moved within the field of view of the optical microscope 603 shown in FIG. 6. As a method, for example, the sample stage 601 is moved in the X-axis and Y-axis directions, and the range to be measured is taken into the field of view of the optical microscope 603. 9 shows this state. In FIG. 9, 901 represents a glass substrate, such as an LCD device, for example, taken into the viewing range (the range enclosed by A, B, C, D) of the optical microscope 603, and 902-1, 902-2. ,… 902-5 represents an electrode formed of aluminum (Al), chromium (Cr), or the like formed on the glass substrate 901. In addition, when representing an electrode, it is called the electrode 902. FIG. 903 and 904 correspond to the measurement reference window PW, which will be described later. LW1 and LW2 correspond to the above-mentioned measurement window LW, and RW1 and RW2 correspond to the above-mentioned measurement window RW. In addition, in FIG. 9, the pair of measurement windows LW1 and RW1 and the pair of measurement windows LW2 and RW2 are shown in order to measure two line | wire widths. 905 shows a registration window for focus.

In step 803, focus adjustment is performed. In the focus adjustment, for example, auto focusing is performed by using the image of the focus registration window 905 so that the light and shade of the luminance signal described above are made clear for the measurement of the line width and the like. In step 804, automatic light amount adjustment is performed. The automatic light amount adjustment adjusts the brightness of the illumination light so as not to become too bright and too dark. Illumination light is a light source (not shown) which illuminates the object 602. In addition, focus adjustment and automatic light quantity adjustment are automatically performed by the instruction | indication from the dimension measurement calculation processing apparatus 606. FIG.

In step 805, pattern matching is performed in the screen area to search for a desired pattern position. That is, using the measurement reference window PW as described above, the position of the same pattern as the pattern registered in advance is searched over the entire screen shown in FIG. This pattern matching method compares the luminance distribution of the measurement reference window PW registered previously, for example, with the luminance distribution of the measurement reference window 903 shown in FIG. 9, and determines whether a pattern is the same.

In step 806, it is determined whether the target pattern has been detected. If the target pattern is not detected (no) as a result of the determination, the flow proceeds to step 807. If the desired pattern is detected (in the case of the example), the flow proceeds to step 812.

In step 812, focus adjustment of the designated area is performed. That is, in step 812, the focus is adjusted again using the focus registration window 905 for the target pattern, and the flow proceeds to step 813. FIG.

In step 813, dimension measurement is started. The dimension measurement measures the line width and the like of the electrode 902 by the method described with reference to FIG. 7 described above. For example, in FIG. 9, in the pair of measurement windows LW1 and RW1, the dimension between the electrode 902-1 and the electrode 902-2 is measured. In addition, in the pair of measurement windows LW2 and RW2, the line width of the electrode 902-4 is measured.

In step 807, it is determined whether to perform a search operation. If the search operation is performed (in the case of the example), the flow proceeds to step 808. If no seek operation is made (No), the process proceeds to step 810. In step 810, pattern matching error display is performed. With the pattern matching error indication, the operator performs the operation of step 811. That is, the operator manually corrects the sample position and retrys. Here, the operator corrects the sample position while looking at the TV monitor, adjusts the position to the target pattern, and proceeds to step 812.

In step 808, it is determined whether the number of searches is 8 or less. If it is 8 times or less (in the case of YES), the flow advances to step 809;

In step 809, the position of the object under test is moved. That is, the position of the measurement object is moved in the X-axis and Y-axis directions at a preset pitch. Then, the steps from the above-described step 805 are repeated.

As described above, using a template registered in advance, pattern matching is performed in the entire imaging area to detect a target pattern, pattern position information of the detected pattern, and a template position registered in advance (measurement reference window PW). The measurement pattern is detected from the relative positions of the measurement windows (measurement window LW and measurement window RW) with respect to each other, and measurement of line width and the like is performed.

However, in the conventional small dimension measuring apparatus, when there are a plurality of similar or identical patterns on the measurement screen of a non-measured object, there are cases where a plurality of target pattern candidates are found by performing pattern matching with a template registered in advance. For example, as shown in FIG. 9, it is detected corresponding to the measurement reference window PW as a pattern 903 or 904 similar or identical to the previously registered pattern. In FIG. 9, two places are detected. In this case, measurement is performed with the pattern closest to the target pattern, but due to variations in contrast, brightness, pattern size, etc. of the pattern, measurement may be performed with the same or similar shape patterns other than the previously registered pattern. That is, although the wiring pattern to be originally measured is the pattern 903, there is a problem that the neighboring pattern 904 is measured.

In addition, if a target pattern is not found at a pre-registered coordinate position, a method of prompting manual positioning by an operator by displaying an error message not only bothers the operator's hand, but also measures until the operator notices and manipulates it. There is a problem that the device is in a stopped state and the operation rate of the device is lowered.

In addition, when the target pattern is not found at the pre-registered coordinate position, a method of finding the target pattern by repeating the pattern matching operation by pitch shifting the stage in the X-axis and Y-axis directions at the pre-registered pitch is performed. Since the pattern matching operation is repeated while pitch shifting, there is a problem that takes a long time. Therefore, the realization of the micro dimensional measuring method and measuring apparatus which solve this problem is calculated | required.

Patent Document 1: Japanese Patent Application Laid-Open No. 2005-69795

In the conventional small dimension measuring method and measuring apparatus, when there exist a plurality of similar or identical patterns on the measurement screen of a non-measured object, it may be measured by the same or similar shape pattern other than the pattern registered previously.

In addition, when the target pattern is not found at the pre-registered coordinate position, there is a problem in that the measuring device is stopped until the operator notices and operates, thereby lowering the operation rate of the device.

In addition, when the target pattern is not found at the pre-registered coordinate position, the method of repeating the pattern matching operation by repeatedly shifting the stage in the X-axis and Y-axis directions at the pre-registered pitch to find the target pattern may pitch the XY stage. Since the pattern matching operation is repeated while moving, there is a problem that takes a long time.

An object of the present invention is to provide a highly reliable method for measuring small dimensions and a measuring apparatus.

Another object of the present invention is to provide a micro dimensional measurement method and a measuring apparatus which can set a range in which similar or identical patterns do not exist in the measurement screen of a non-measured object.

Another object of the present invention is to provide a micro-dimension measuring method and a measuring device in which the measurement screen of a non-measured object is enlarged, the range of which can be automatically searched is increased, and the probability of pattern matching is increased.

It is still another object of the present invention to provide a micro dimensional measurement method and a measuring device which enlarge a measurement screen of a non-measured object, change the search range electronically, and perform pattern matching.

In the small size measuring method of the present invention, in a small size measuring method in which a predetermined portion of a measurement object is enlarged and imaged by a TV camera, and the size of a predetermined pattern is measured by image processing from the image of the captured TV camera. A search reference window for detecting a search area of a predetermined size and the predetermined pattern by pattern matching is set on the image of the TV camera, and the measurement reference window is appropriately located within the search area of the predetermined size. Move to detect the predetermined pattern.

Further, in the micro-dimensional measurement method of the present invention, the search reference window of the predetermined size is appropriately moved on the image of the TV camera, and the measurement reference window is suitably moved within the moved search area of the predetermined size. Move to detect the predetermined pattern by the pattern matching.

Moreover, in the small dimension measuring method of this invention, the said search area of predetermined size is comprised so that it may become a size which does not contain two or more said predetermined patterns.

In addition, the micro-dimension measuring apparatus of the present invention includes a sample stage, a target object mounted on the sample stage, a TV camera unit for enlarging and capturing a predetermined portion of the target object, and an image captured by the TV camera unit. And an image processing unit for displaying an image processed by the image processing unit, and the image processing unit includes a pattern matching processing unit and a dimension measuring operation unit for detecting a predetermined pattern of the object to be measured by pattern matching. And the pattern matching processing unit is configured to set a search area having a predetermined size on the image and a measurement reference window for detecting the predetermined pattern by pattern matching, and the measurement reference window within the search area having the predetermined size. By appropriately moving the measurement reference window by appropriately moving the inside of the search area having the predetermined size. It is configured to detect the predetermined pattern group.

As described above, according to the present invention, even when there are a plurality of identical or similar patterns on the measurement screen, it is possible to realize a micro dimensional measuring method and a measuring device capable of reliably detecting a predetermined pattern. In addition, since the measurement screen of a non-measured object can be enlarged, the range that can be automatically searched can be widened, and the probability of detecting pattern matching can be increased. Therefore, when a target pattern is not found at a pre-registered coordinate position. The troublesomeness of the operator can be reduced, and the operation rate of the measuring device can be improved. In addition, since the measurement screen is made larger by measuring the non-measured object, the search range is changed electronically, and pattern matching is performed, it is not necessary to repeat the pattern matching operation by pitch shifting the XY stage so that the tact time can be reduced. It has the characteristics.

1 is a flow chart for explaining the operation of an embodiment of the present invention;
2 is a block diagram of a schematic configuration of an embodiment of the present invention;
3 is a view showing a TV monitor screen for explaining an embodiment of the present invention;
4 is a view showing a TV monitor screen for explaining the movement of the search area according to an embodiment of the present invention;
5 is a view showing an LCD substrate for explaining a measuring point of an embodiment of the present invention;
6 is a block diagram of a schematic configuration of an example of a conventional small dimension measuring device;
7 is a view for explaining the principle of a conventional method for measuring small dimensions,
8 is a flowchart for explaining the operation of the conventional method for measuring small dimensions;
9 is a view showing a TV monitor screen for explaining a conventional method for measuring small dimensions,
10 is a view showing a TV monitor screen for explaining another embodiment of the present invention;
11 is a view showing a TV monitor screen for explaining another embodiment of the present invention.

EMBODIMENT OF THE INVENTION Embodiment which concerns on this invention is described using drawing. 1 is an operation flowchart for explaining an embodiment of the present invention. 2 shows an embodiment of a micro dimensional measuring device used in the present invention. 2, the same code | symbol is attached | subjected to the same thing as FIG. 201 is an image processing unit. This image processing unit 201 includes a pattern matching processing unit 202 and a dimension measurement calculation processing unit 203. In addition, the pattern matching processing unit 202 and the dimension measurement calculation processing unit 203 may be integrally configured. 204 denotes an XY stage on which the measurement object 602 is mounted, and 205 denotes a driving unit of the XY stage 204. This micro-dimension measuring apparatus enlarges the electrode pattern formed on the glass substrate of the to-be-measured object 602, for example, the LCD apparatus, with the optical microscope 603, and projects it on the imaging part 605 of the TV camera 604. The spatial image of the surface of the projected object 602 is picked up by the imaging unit of the TV camera 604, converted into an image signal, and supplied to the pattern matching processing unit 202 of the image processing unit 201. The pattern matching processing unit 202 detects a desired pattern according to the operation flowchart shown in FIG. Then, the dimension measurement calculation processing unit 203 processes the video signal of the desired pattern, electrically calculates the dimensions of the desired portion of the object under test 602, and the TV monitor 607 of the object under test 602 is used. Display images and dimensional measurements.

Next, an embodiment of the present invention will be described in detail with reference to FIG. 1. In Fig. 1, first, in step 101, measurement is started. In step 102, the predetermined measurement portion of the measurement object 602 is moved into the field of view of the optical microscope 603. This will be described with reference to FIG. 5. FIG. 5 is an explanatory diagram when a display portion of an LCD device is created, for example. 501 is a glass substrate, and this glass substrate 501 is 1100 mm x 1300 mm, for example. In this glass substrate 501, for example, six LCD display screens of display portions (screens) 502-1, 502-2, ..., 502-6 are formed. 5 is an example, and needless to say, the number of screens that can be divided according to the size of the glass substrate and the size of the display screen of the LCD is different. And P1, P2,... P9 denotes a measurement point of the display screen 502-1 of the LCD, for example, a 15-inch display screen. In addition, when a measuring point is represented, it shall be called measuring point P. FIG. In addition, in a present Example, although a measurement point shows 9 points, for example, it is not specifically limited to 9 points. As for the position of each measurement point P, the X position and the Y position are previously written to the memory | storage part (not shown) of the pattern matching process part 202 by the input part 608. FIG. The same applies to the other display screens 502-2, 502-3, ..., 502-6.

Therefore, when the glass substrate 501 is mounted on the XY stage (sample stage) 204, and step 102 is operated, the image processing unit 201 drives the XY stage 204 through the driving unit 205, for example. , The image of the measuring point P1 is taken into the field of view of the microscope 603. 3 shows this state. 3, the same code | symbol is attached | subjected to the same thing as FIG. In Fig. 3, reference numeral 301 denotes a pattern matching search area (hereinafter, abbreviated as search area), and 302-1 and 302-2 denote display for indicating pairs of measurement windows LW1 and RW1 or pairs of measurement windows LW2 and RW2. Indicates. This pair display will be described later.

In step 103, focus adjustment is performed, and in step 104, automatic light amount adjustment is performed. This is the same as that of steps 803 and 804 of the flowchart explained in FIG. 8, and thus description thereof is omitted.

In step 105, pattern matching is performed in the search area. This will be described in more detail. Pattern matching in a search area means pattern matching in the search area 301 shown in FIG. Here, the search area 301 is set to a size in which only one of the same patterns is entered, for example. For example, when a predetermined pattern is detected by pattern matching using the reference measurement window PW, the length in the X-axis direction of the search area 301 is XS and the length in the Y-axis direction is YS, and the electrode 902-1 And the distance between the electrode 902-2 and the electrodes 902-2 and 902-3 as T1 and the width of the electrode 902-2 as D1, the length XS in the X-axis direction is represented by the formula (2). It is set to a range.

T1 <XS <(2T1 + D1)... (2)

On the other hand, the length YS in the Y-axis direction is not particularly limited in the pattern as shown in FIG. 3, but may be appropriately determined in consideration of arithmetic processing time for pattern matching and the like. For example, it may be set to the same length as the length XS in the X-axis direction. In FIG. 3, XS = YS is set. The length XS in the X-axis direction and the length YS in the Y-axis direction are not limited to the above equation (2), but are appropriately set depending on the pattern of the object to be imaged, but there is only one same pattern to be detected. Needless to say, it is set to a size that doesn't fit.

When the search area 301 is determined, a predetermined pattern is detected by pattern matching using the reference measurement window PW in the search area 301. In the detection method, for example, the angle at the upper left of the reference measurement window PW matches the angle at the upper left of the search area 301, and the luminance distribution of the reference measurement window PW at this position is registered in advance. Compare the luminance distribution of the known patterns. If they do not match, for example, the reference measurement window PW is moved in the direction of one pixel X axis, and the luminance distribution of the reference measurement window PW is compared with the luminance distribution of the known pattern registered in advance. This is sequentially repeated, pattern matching is performed for all the areas in the search area 301, and the position of the pattern that matches the luminance distribution of the known pattern registered in advance is detected. In addition, it is needless to say that the movement of the reference measurement window PW in the search area 301 is performed by cutting out an electronic image that moves the pixel, and does not drive the XY stage.

In step 106, it is determined whether the target pattern has been detected. That is, when the target pattern is found by the pattern matching in the search area 301 in step 105, the process proceeds to step 111, and when the target pattern is not found, the process proceeds to step 107.

In step 111, focus adjustment of the designated area is performed. That is, in step 111, similarly to step 812, focus adjustment is again performed using the focus registration window 905 for the target pattern, and the flow proceeds to step 112. FIG.

In step 112, the dimensional measurement is started. The dimension measurement measures the line width and the like of the electrode 902 by the method described with reference to FIG. 7 described above. For example, in FIG. 3, in the pair of measurement windows LW1 and RW1, the dimension between the electrode 902-1 and the electrode 902-2 is measured. In addition, in the pair of measurement windows LW2 and RW2, the line width of the electrode 902-4 is measured.

In step 107, it is determined whether to perform a search operation. If the search operation is performed (in the case of the example), the flow proceeds to step 108. If no search operation is performed (No), the process proceeds to step 109. In step 109, pattern matching error display is performed. By this pattern matching error indication, the operator performs the operation of step 110. That is, the operator manually corrects the position of the measured object and retry. Here, the operator corrects the position of the object under measurement while watching the TV monitor, aligns it with the desired pattern, and proceeds to step 111.

However, the search operation of step 107 will be described in detail with reference to FIG. FIG. 4 shows a measurement screen in which a predetermined portion of the measurement target 602 is enlarged by the microscope 603 as in FIG. 3, and the image captured by the TV camera 604 is displayed on the TV monitor 607. And (a), (b),... , (i) shows nine search areas 301. That is, the search area a represents the range represented by a1, a2, a3, a4, and corresponds to the search area 301 of FIG. The search area b is a range represented by b1, b2, b3, b4, and the search area c is a range represented by c1, c2, c3, c4. The other search area is also the same, and the search area i has shown the range shown by i1, i2, i3, i4.

First, in the search area a, pattern matching is performed using the reference measurement window PW in the search area a in step 105. When the target pattern is not detected by this pattern matching, the search area is moved to the search area b, and similarly, pattern matching is performed using the reference measurement window PW in the search area b. By repeating this sequentially, the search area moves to the search area i. That is, in step 107, it is determined whether or not the number of search times is equal to 8 times. If it is 8 times or less (in the case of an example), the process proceeds to step 108, where the above-described search area is sequentially moved to perform pattern matching. If it is 8 times (No), the process proceeds to step 109. After step 109 is as described above.

As described above, when the target pattern is not found in the search area a, the search area 301 is moved to (b), and pattern matching is performed as described above to find the target pattern. If not found, select (c), (d),... Until the desired pattern is found. , the movement of the search area 301 and the pattern matching operation are further repeated in the order of (i). When the target pattern is found in this process, as in the above, the image of the focus registration window 905 is used, for example, the auto focusing of the image contrast method is performed, and dimensions are measured in the same manner as described in FIG. Initiate. For example, in FIG. 3, in the pair of measurement windows LW1 and RW1, the dimension between the electrode 902-1 and the electrode 902-2 is measured. In addition, in the pair of measurement windows LW2 and RW2, the line width of the electrode 902-4 is measured.

Here, the positions of the search areas (a) to (i) can be automatically calculated from the information of the pitch in the X-axis direction and the pitch in the Y-axis direction registered in advance. In addition, since the movement of the search area 301 is processed on the image memory of the pattern matching processing unit 202, it is not necessary to move the XY stage. Thus, by setting the search area 301 in the measurement screen shown in FIG. 3, the probability of detecting the same or similar pattern can be greatly reduced. Or since it can be made into none, the detection precision of pattern matching can be improved remarkably. In addition, there is a feature that can reduce the inspection time. In addition, by setting the search area 301 in the measurement screen in this way, the probability of detecting the same or similar pattern can be greatly reduced or eliminated. Therefore, the magnification of the optical microscope 603 can be reduced to reduce the TV. Since the measurement screen taken in from a camera can be enlarged, there exists a characteristic which can enlarge the test | inspection range of the object 602 which can be measured once.

In addition, although the movement of a search area was demonstrated as eight times in this Example, it is not limited to this, It can set suitably according to the magnitude | size of a test subject, a test objective, or the shape of a pattern. For example, the direction of the search area a may be designated N times x M pitches in the positive or negative direction with respect to each of the X and Y axes. In addition, when there is no pattern information in the search area, the pattern matching operation in the search area is not performed. Therefore, the inspection time can be shortened by shifting.

As described above, for example, the measuring points P1, P2,... , Line width, etc. are measured for all P9. And when one LCD display screen 502-1 is complete | finished, similarly to this, the measurement of all the measuring points P of the LCD display parts 502-2, 502-3, ..., 502-6 shown in FIG. 5 is performed sequentially. Do it. That is, the line width measurement is completed by performing the measurement point P of 54 points in total. In the case of such a large area and a large number of measurement points P, the present invention has a feature that the detection accuracy of pattern matching can be improved remarkably and the inspection time can be shortened.

10 is a view for explaining another embodiment of the present invention. In addition, the code | symbol of each part of FIG. 10 corresponds to the code | symbol of FIG. In the embodiment shown in FIG. 10, in step 109 shown in FIG. 1, when a pattern matching error occurs, the pattern matching error is displayed. In the present embodiment, the pattern matching error can be easily notified to the operator by displaying the reference measurement window 301 in color or by performing a diagonal line, a mesh display, or the like. In addition, when an operator is far apart etc., it can also make it sound with a buzzer.

11 is a view for explaining another embodiment of the present invention. Here, FIG. 11 shows, for example, a measurement screen in which a predetermined portion of the measurement object 602 is enlarged by the microscope 603 and the image captured by the TV camera 604 is displayed on the TV monitor 607. In FIG. 11, 901 is an image which shows the glass substrate of the non-measurement 602, for example, LCD. 1101-1, 1101-2, and 1101-3 show electrodes formed on the glass substrate 901, and 1102-1, 1102-2, and 1102-3 show an image of a gap between the electrodes 1101. As described in the above embodiment, the measurement windows LW and RW were used to measure the electrode width or the distance between the electrodes.

However, as shown in Fig. 11, when there are a plurality of measurement points, for example, when there are a plurality of pairs of measurement windows LW1-RW1, a pair of measurement windows LW2-RW2, and a pair of measurement windows LW3-RW3, they are present in the TV monitor 607. When displayed, a case arises in which an operator cannot distinguish which measurement window is a pair of measurement windows. In particular, when measuring between different electrodes, such as a pair of measuring windows LW2-RW2. Therefore, in order to clarify the pair of measurement windows, the line segments 302-3, 302-4, and 302-5 connecting the pairs of measurement windows are displayed. In this way, the operator can easily distinguish the pair of measurement windows. In addition, the line segments 302-1 and 302-2 shown in FIG. 3 are also the same effect. It is needless to say that in order to distinguish between the pairs of measurement windows, a method such as changing the color or displaying a mesh in addition to the line segment 302 can be easily performed.

As mentioned above, although this invention was demonstrated concretely, this invention is not limited to the Example of the micro dimensional measuring method and measuring apparatus described here, It can be said that it can be widely adapted to the micro dimensional measuring method and measuring apparatus of that excepting the above. There is no need.

201: control unit
202: pattern matching processing unit
203: dimension measurement calculation processing unit
204, 601: sample table
205: sample stage drive unit
301: search area
302: line segment representing a pair of measurement windows
PW, 903, 904: Reference window,
LW, RW: Measuring window
501, 901: glass substrate
502: LCD display unit
602: measured object
603: optical microscope
604: TV camera
605: imaging unit
606: dimension measurement operation processing unit
607: TV monitor
608: input unit
701: monitor screen
702: scan line
703: wiring pattern
902, 1101: electrode
905: focus registration window
1102: electrode gap

Claims (2)

In the small dimension measuring method which enlarges the predetermined part of a to-be-measured object, and image | photographs with a TV camera, and measures the dimension of a predetermined pattern by the image processing from the image of the said captured said TV camera,
A search reference window for detecting a search area of a predetermined size and the predetermined pattern by pattern matching is set on the image of the TV camera, and the measurement reference window is appropriately located within the search area of the predetermined size. Moving to detect the predetermined pattern
Micro-dimension measuring method characterized by the above-mentioned.
Sample bed,
The object to be mounted on the sample stage;
A TV camera unit for enlarging and capturing a predetermined portion of the measured object;
An image processing unit which performs image processing on the image picked up by the TV camera unit;
A display unit for displaying an image processed by the image processing unit
With
The image processing unit includes a pattern matching processing unit and a dimension measurement operation unit for detecting a predetermined pattern of the object to be measured by pattern matching,
The pattern matching processing unit,
A function of setting a search area of a predetermined size on the image and a measurement reference window for detecting the predetermined pattern by pattern matching;
Has a function of appropriately moving the measurement reference window within the search area of the predetermined size,
Detecting the predetermined pattern by appropriately moving the measurement reference window within the search area of the predetermined size.
Micro-dimension measuring device characterized in that.

Images