JP5418964B2 - TFT array inspection apparatus and pixel coordinate position determination method - Google Patents

Description

  The present invention relates to an array inspection of a TFT array substrate or the like, and more particularly to determination of a coordinate position of a pixel of a panel.

  In electrical inspection of a TFT array substrate, an inspection method using a potential contrast is known as a technique for measuring the potential of a sample without contact. According to this potential contrast, the potential of the sample can be measured by measuring the energy of secondary electrons emitted from the sample surface by irradiating the sample with an electron beam.

  In this TFT array inspection apparatus, a predetermined pattern inspection signal is applied to a TFT array substrate used for a liquid crystal display, an organic EL display, etc., and a predetermined potential state is applied. This substrate is irradiated with an electron beam and generated from the TFT substrate. Secondary electrons are detected, whether or not a predetermined voltage is applied to the panel of the substrate is measured by a signal obtained from the secondary electrons, and a panel defect such as a short circuit is determined based on the measurement result. For example, Patent Document 1 is known as such a TFT array inspection apparatus.

  In the TFT array inspection apparatus, the electron beam scanning on the substrate is performed by moving the electron beam irradiated from the electron gun in the x direction and moving the substrate in the y direction, for example. In the scanning by the swing of the electron beam and the movement of the substrate, in order to inspect a large substrate, a plurality of electron guns are arranged in the x direction, and each electron gun has a plurality of paths divided into strips in the x direction. As a unit. For example, Patent Documents 1-4 are known as a configuration including a plurality of electron guns.

  In the TFT array inspection, defective pixels are detected based on a secondary electron image obtained by scanning an electron beam on a substrate. Since the defective pixel is determined by specifying the coordinate position of the pixel on the substrate, it is necessary to obtain the coordinate position of the pixel from the secondary electron image.

  One substrate is divided into a plurality of scanning ranges, and an electron gun is provided in each scanning range, and each electron gun divides and scans the scanning range that each of them divides into a plurality of passes. The next electron image is a pass unit and an electron gun unit.

  In order to identify the pixels on the substrate, it is necessary to combine the multiple secondary electron images obtained for each pass and electron gun, and obtain the coordinate position of the pixel for the secondary electron image of the entire substrate obtained. is there.

  In order to obtain the coordinate position of the pixel, in the secondary electron image obtained by the pass unit and the electron gun unit, first, the coordinate position with respect to the substrate is specified for the pixel at the head of the secondary electron image, and this coordinate position is used as a reference. Determining the coordinate position of the pixel is performed.

  Conventionally, in order to specify the coordinate position of the pixel at the head of the secondary electron image with respect to the substrate, the pixel at the head of the panel in the synthesized secondary electron image is used as a reference and calculated from the pixel at the top of the panel by calculation. ing.

  FIG. 11 is a diagram for explaining a conventional method of calculating the coordinate position of a pixel from a secondary electron image.

  The example shown in FIG. 11 shows a case where two electron guns Xn and Xn + 1 are provided, and each electron gun performs scanning by four passes of pass 1 to pass 4. Here, as secondary electron images, a part of the path 1 and the path 4 of the electron gun Xn and a part of the path 1 of the electron gun Xn + 1 are shown.

  Here, in the secondary electron image 200 by the electron gun Xn, the pixel at the head of pass 1 is the panel head pixel 101, and the coordinate position of the pixel on the secondary electron image is the coordinate position [x, y] as the reference coordinate. Determine. Since the inter-pass secondary electron images 201 to 204 and 211 to 214 obtained in each scan are in units of passes and electron guns, for example, in order to specify the coordinate position of the pixel, for example, the first pixel of each secondary electron image The coordinate position is obtained with respect to the reference coordinates.

  For example, for the secondary electron image 204 obtained in pass 4 of the electron gun Xn, the coordinate position [x + d, y] of the inter-pass head pixel 104 is set to the coordinate position [x, d of the panel head pixel 101 located at the corner of the panel. y] as a reference. In this calculation, for example, the distance d in the x direction from the first pixel 104 between passes is obtained based on the length of each pixel in the x direction, the number of pixels in each pass in the x direction, and the like. This is done by adding to the coordinate position x of the first pixel 101.

  Also, for the secondary electron image 211 obtained in pass 1 of the electron gun Xn + 1, the coordinate position [x + D, y] of the inter-electron gun top pixel 111 is set to the panel top pixel 101 in the same manner as the inter-pass head pixel. The coordinate position [x, y] is calculated as a reference.

JP 2004-325097 A JP 2004-309488 A JP 2004-271516 A JP 2004-125564 A

  As described above, the coordinate position of the first pixel between passes on the TFT substrate and the coordinate position of the first pixel between electron guns are actually obtained because they are calculated from the panel first pixel at the panel corner of the secondary electron image. It is not based on secondary electron images. Therefore, in an image obtained by combining multiple secondary electron images, if each secondary electron image is misaligned between passes or electron guns, or if there is fluctuation in the secondary electron image, it is true. There is a problem in that a positional deviation occurs between the coordinate position of each other.

  In this way, if there is a deviation between the coordinate position of the first pixel between passes or the first pixel between electron guns and the true coordinate position, the coordinate position of the first pixel between passes or the first pixel between electron guns is used as the basis. When the coordinate position of the defective pixel is obtained, there is a problem that a positional deviation also occurs in the coordinate position of the defective pixel.

  SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-described problems and to obtain the coordinate position of a pixel in a secondary electron image without displacement.

  The present invention corrects this misalignment even when misalignment occurs in the secondary electron image by making the boundaries between adjacent secondary electron images continuous in a plurality of secondary electron images. The coordinate position of the pixel is obtained without displacement.

  The continuation of the secondary electron image of the present invention is applied not only to a secondary electron image of a plurality of passes obtained by scanning with one electron gun, but also to a secondary electron image of a divided area scanned by each electron gun. can do.

  The boundary of the secondary electron image of the present invention is applied to the secondary electron image obtained by applying a predetermined inspection signal to the substrate, which forms a different signal pattern in adjacent pixels, and applying this inspection signal. When the signal pattern of a pixel at a specific position is detected and this signal pattern is compared with the signal pattern of the pixel at the same position that is assumed by applying an inspection signal. In this case, an adjacent pixel is defined as a true pixel as a misalignment.

  In addition, in this case, in the secondary electron image adjacent between the paths and the secondary electron image adjacent between the electron guns, the pixels that are discontinuous at the boundary position are displaced. This means that pixel discontinuity is eliminated by moving the pixel.

  The present invention can be in two forms: a TFT array inspection device and a pixel coordinate position determination method.

  An aspect of the TFT array inspection apparatus of the present invention is a TFT array inspection apparatus that inspects a TFT array of a panel by detecting secondary electrons obtained by scanning an electron beam on a panel formed on the substrate. A plurality of electron guns that irradiate a plurality of electron beams, a plurality of detectors that detect a plurality of secondary electrons obtained by scanning each electron beam, and an inspection signal applied to the TFT array of the panel, Signal processing for obtaining a plurality of secondary electron images from detection signals from a plurality of detectors, and detecting defects in each pixel of the panel based on the secondary electron images, and inspection signal applying means for forming a potential distribution of a predetermined pattern A part.

  The signal processing unit makes the boundary between adjacent secondary electron images continuous in the plurality of secondary electron images by the continuation processing unit.

  In the continuation of the boundary of the electronic image, one form makes the secondary electron image by the adjacent electron gun continuous, and the other form makes the secondary electron image by the adjacent path continuous.

  In the form of continuation of secondary electron images by adjacent electron guns, each electron gun scans an area where the panel is divided, and the continuation processing unit performs adjacent division in the secondary electron image obtained in each divided area. The boundary of the secondary electron image of the region is made continuous.

  In a form in which secondary electron images by adjacent passes are made continuous, each electron gun divides and scans each scanning region by a plurality of passes, and the continuation processing unit is in the secondary electron image obtained by each pass, The boundaries of secondary electron images in adjacent paths are made continuous.

  In addition, each electron gun can be divided into a panel and scanned, and each scanning region can be divided and scanned in a plurality of passes. In the secondary electron image obtained in the pass, the boundary of the secondary electron image in the adjacent pass is made continuous, and in the secondary electron image obtained in each divided region, the boundary of the secondary electron image in the adjacent divided region is made continuous. To do.

  The continuous processing unit compares the signal pattern of the pixel at the end position of the secondary electron image with the signal pattern of the pixel corresponding to the end position calculated based on the pixel size from the end of the panel, If the two signal patterns do not match, the boundary between adjacent secondary electron images is made continuous by shifting the secondary electron image by one pixel.

  The inspection signal applied by the inspection signal applying means can be a signal pattern that forms a potential distribution of a lattice pattern on the panel.

  An aspect of a pixel coordinate position determination method according to the present invention is a method of determining a coordinate position of a pixel included in a TFT array panel with respect to a substrate of the pixel, scanning an electron beam in each divided region on the substrate, A plurality of secondary electrons obtained by scanning are detected, a secondary electron image is obtained for each region, and the boundary of adjacent secondary electron images is continuously processed for a plurality of secondary electron images. The coordinate position of the pixel of the processed secondary electron image is determined as the coordinate position of the pixel of this panel.

  The continuation processing compares the signal pattern of the pixel at the end position of the secondary electron image with the signal pattern of the pixel corresponding to the end position calculated based on the pixel size from the end of the panel. If the signal patterns of the second and second signal patterns do not match, the boundary between adjacent secondary electron images is made continuous by shifting the secondary electron image by one pixel.

  The signal pattern may be a lattice pattern. In this case, a signal pattern inspection signal that forms a potential distribution of the lattice pattern on the panel is applied to the TFT array of the panel, and the lattice pattern is formed on the panel. A secondary electron image is obtained by scanning the electron beam in each region of the substrate on which the potential distribution of the lattice pattern is formed and the potential distribution of the lattice pattern is formed.

  According to the aspect of the present invention, it is possible to continue between the paths of the secondary electron image composed of a plurality of passes, and to continue between the electron guns of the secondary electron image by the plurality of electron guns. .

  According to the aspect of the present invention, even if the secondary electron image composed of a plurality of passes is shifted in the y direction, the positional accuracy is not affected.

  According to the aspect of the present invention, since the end of the panel can be automatically detected, manual input of the panel corner can be eliminated.

  According to the present invention, the coordinate position of a pixel in a secondary electron image can be obtained without being displaced.

It is the schematic for demonstrating the structure of the TFT array test | inspection apparatus of this invention. It is operation | movement explanatory drawing for demonstrating the flow of the data processing of this invention. It is a figure for demonstrating the relationship of the secondary electron image between paths, and the relationship of the secondary electron image between electron guns. It is a flowchart for demonstrating the process which makes a secondary electron image continuous. It is a figure for demonstrating the positional relationship of an adjacent secondary electron image. It is a figure for demonstrating the positional relationship of an adjacent secondary electron image. It is a figure for demonstrating the positional relationship of an adjacent secondary electron image. It is a figure for demonstrating the positional relationship of an adjacent secondary electron image. It is a figure for demonstrating the relationship between the gate line of a panel, and a source line. It is an example of the test | inspection signal which forms a grid | lattice-like electric potential distribution. It is a figure for demonstrating the method to calculate the coordinate position of a pixel from the conventional secondary electron image.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic view for explaining the configuration of a TFT array inspection apparatus according to the present invention.
In FIG. 1, a TFT array inspection apparatus 1 irradiates an electron beam from a plurality of electron beam sources 6 onto a panel (not shown) on a substrate 10 and emits secondary electrons emitted from the panel to a plurality of secondary electrons. An example of the configuration of an inspection apparatus that detects defects of a TFT array by detecting with an electron detector 7 is shown.

  The substrate 10 is placed on the XY stage 5 and is movable in the X direction and the Y direction. The scanning control circuit 3 controls the movement of the XY stage 5 in the X / Y direction and the deflection of the electron beams emitted from the plurality of electron beam sources 6 to scan the electron beam on the substrate, thereby allowing the entire surface of the panel to be scanned. Is irradiated with an electron beam. The scanning control circuit 3 is controlled by an inspection control circuit 2 that controls the entire TFT array inspection apparatus 1.

  When detecting defects in the TFT array, an inspection signal is applied to the TFT array of the panel of the substrate 10 to form a potential state of a predetermined pattern on the panel, and this potential state is detected by scanning an electron beam. . The inspection signal application circuit 4 applies an inspection signal to the TFT array. The inspection signal has a signal pattern corresponding to the defect type detected by the TFT array.

  The TFT array inspection apparatus 1 of the present invention includes a signal processing unit 8 and inputs a detection signal detected by the secondary electron detector 7 to perform signal processing for detecting a defect in the TFT array.

  The signal processing unit 8 shown in FIG. 1 shows a circuit example. The signal processing unit 8 receives a detection signal detected by the secondary electron detector 7 to form a detection data 8a, an allocation unit 8b that allocates the detection data to the pixels of the panel, and a normalization that normalizes the detection data Unit 8c, a continuation processing unit 8d for correcting pixel positional deviation by performing continuation between secondary electron images formed in pass units and continuation between secondary electron images formed in electron gun units , Combining the secondary electron image of the continuous path and the secondary electron image of the electron gun to form a secondary electron image of the entire panel, and detecting defective pixels from the secondary electron image A defective pixel detector 8f is provided.

  The normalization unit 8c uses the detection data detected by the detection circuit 8a as it is to form normalized data, and also assigns the detection data detected by the detection circuit 8a to each pixel of the panel and performs detection that represents each pixel. Data may be obtained, and normalized data may be formed from the detection data assigned to each pixel.

  The defective pixel detection unit 8f is configured to detect a defect in the TFT array, compares the normalized signal intensity with a threshold value obtained with a normal pixel, and detects a defective pixel based on the comparison result.

  When the defective pixel is specified by the signal processing unit 8, the detection data allocated to each pixel by the allocation unit 8c is normalized by the normalization unit 8c, and the normalized data is shifted by the continuation processing unit 8d. Is corrected and synthesized by the data synthesis unit 8e to form secondary electron image data corresponding to one panel, and the defective pixel detection unit 8f compares the detection data with a threshold value to extract defective pixels.

  In addition, each structure 8a-8f of the signal processing part 8 was shown in order to demonstrate the function by TFT array test | inspection of this invention, and does not necessarily have a separate structure part which implement | achieves these functions, You may comprise by the circuit comprised with CPU, memory, etc., and the software which performs each function.

The flow of data processing in the present invention will be described with reference to the operation explanatory diagram of FIG.
First, secondary electrons are detected by scanning the substrate panel with an electron beam to obtain detection data. This detection data represents the potential state at the point where the electron beam is irradiated on the panel. This detection data is detected for each secondary electron detector. The three raw data shown in FIG. 2 irradiate an electron beam with three electron beam sources, detect secondary electrons with three secondary electron detectors, respectively, and use the detected data as raw data. By performing allocation, normalization, serialization, and synthesis, detection data of the secondary electron image of the entire panel surface of the substrate is formed.

  In FIG. 2, three raw data are detected data detected from a scanning area detected by an electron beam source and a secondary electron detector arranged on the left side of the substrate, and an electron beam source arranged in the center of the substrate. The detection data detected from the scanning area detected by the secondary electron detector and the detection data detected from the scanning area detected by the electron beam source and the secondary electron detector arranged on the right side of the substrate are shown. ing.

  The electron beam irradiation points described above do not correspond one-on-one to the pixels of the panel. For example, the detection accuracy may be increased by making a plurality of irradiation points correspond to one pixel. Therefore, detection data (raw data) obtained at a plurality of irradiation points is associated with each pixel. This association of detection data (raw data) with pixels is called allocation processing. In FIG. 2, four pieces of detection data (raw data) are associated with one pixel by the allocation process (S2).

  Next, the signal intensity of the detection data assigned to the pixels is normalized to obtain a signal intensity representing each pixel. By normalizing, fluctuations in signal intensity due to changes in substrate type and scanning conditions can be eliminated.

  Next, the secondary electron images between the passes are made continuous, and further, the secondary electron images between the electron guns are made continuous to correct the displacement of the secondary electron images and pixels, and these secondary electron images are synthesized. Thus, a secondary electron image of one panel is formed. Defect detection is performed based on the secondary electron image obtained by continuous synthesis.

  Hereinafter, the continuation of the secondary electron image will be described with reference to FIGS. FIG. 3 is a diagram for explaining the relationship between secondary electron images between paths and the relationship between secondary electron images between electron guns, and FIG. 4 is a flowchart for explaining processing for making secondary electron images continuous. 5 to 8 are diagrams for explaining the positional relationship between adjacent secondary electron images.

  The example shown in FIG. 3 shows a case where two electron guns Xn and Xn + 1 are provided, and each electron gun performs scanning by four passes of pass 1 to pass 4 as in the example shown in FIG. . Here, as secondary electron images, a part of the path 1 and the path 4 of the electron gun Xn and a part of the path 1 of the electron gun Xn + 1 are shown.

  Here, in the panel secondary electron image 200 by the electron gun Xn, the pixel at the head of pass 1 is the panel head pixel 101, and the coordinates of the pixels on the secondary electron image are set with the coordinate position [x, y] as the reference coordinates. Determine the location.

  The electron gun Xn scans the area assigned to the electron gun Xn through pass 1 to pass 4, and acquires four inter-pass secondary electron images 201 to 204. On the other hand, the electron gun Xn + 1 scans the area assigned to the electron gun Xn + 1 by pass 1 to pass 4, and acquires four inter-pass secondary electron images 211 to 214. The total secondary electron image of the panel can be obtained by serializing and synthesizing these eight interpass secondary electrons 201-214.

  Since the inter-pass secondary electron images 201 to 204 and 211 to 214 obtained in each scan are in units of passes and electron guns, each secondary is determined in the same manner as in the example of FIG. 11 in order to specify the coordinate position of the pixel. The coordinate position of the first pixel of the electronic image is obtained with respect to the reference coordinates.

  In FIG. 3, the first pixel of the inter-pass secondary electron image 201 of pass 1 of the electron gun Xn is the panel start pixel 101, and the first pixel of the inter-pass secondary electron image 204 of pass 4 of the electron gun Xn is also the start of inter-pass. The first pixel of the inter-secondary electron image 211 in the pass 1 of the electron gun Xn + 1 is the inter-electron gun first pixel 111.

  In the secondary electron image of the electron gun Xn, the boundary between the secondary electron images 201 and 202 between the paths forms a path boundary 301, and the boundary between the secondary electron images 202 and 203 between the paths forms a path boundary 302, The boundary between the secondary electron images 203 and 204 between the paths forms a path boundary 303. The boundary between the interpass secondary electron image 204 of the path 4 of the electron gun Xn and the interpass secondary electron image 211 of the path 1 of the electron gun Xn + 1 forms an electron gun boundary 401.

  In the continuous processing according to the present invention, between the secondary electron images of adjacent passes, it is determined whether or not there is a positional shift in the secondary electron image using the signal pattern of the first pixel between the passes, and there is a positional shift. In this case, the secondary electron image is shifted by one pixel so that the position actually measured from the secondary electron image matches the position set in the design.

  In the flowchart shown in FIG. 4, the signal pattern of the pixel 101 at the panel head position is detected. Note that the flowchart of FIG. 4 shows an example in which the secondary electron image between passes is made continuous, but the same can be applied to the continuation of the secondary electron image between electron guns.

  Further, here, as a signal pattern, for convenience, the signal intensity of the secondary electron image is represented by the color of the pixel. This color does not necessarily represent the display color but may be the display density, and represents the signal strength of the pixel for convenience.

  For example, in the pixel color obtained from the secondary electron image, the color of the pixel 101 at the top position of the panel is represented by PCo, the color of the pixel 104 at the top position between passes is represented by PCi, and is set by design based on the reference position. The color of the pixel 104 at the head position between passes is represented by PCth.

  First, the color PCo of the pixel 101 at the panel head position is detected (S1), and the color PCi of the pixel 104 at the head position between passes is detected from the secondary electron image (S2).

  Further, the color PCth of the pixel 104 at the head position between passes set in the design is calculated using the detected color PCo of the pixel 101 at the head position of the panel. The color PCth can be calculated from the positional relationship between the pixel 101 at the panel head position and the pixel 104 at the head position between passes. For example, it is possible to obtain the number of pixels from the reference pixel 101 to the pixel 104 and convert the change in the signal pattern corresponding to the number of pixels. As an example, when the signal pattern is a grid pattern, the colors appear alternately. Therefore, the color PCth of the pixel 104 at the head position between passes is determined depending on whether the number of pixels from the pixel 101 to the pixel 104 is odd or even. (S3).

  For the pixel at the head position between passes, the color PCi detected in the step S2 is compared with the color PCth calculated in the step S3 (S4).

  If the color PCi and the color PCth match in the comparison step of S4, it indicates that the pixel position actually measured from the secondary electron image matches the pixel position determined by design. This is because, for example, when the signal pattern of adjacent pixels is alternately different like a grid pattern, if the amount of misalignment does not exceed two pixels, if there is no misalignment, the color PCi This is because the color PCth matches the color PCth, and the color PCth does not match the color PCth when the position is shifted by one pixel.

  In addition, when the amount of positional deviation exceeds 2 pixels, it can respond by using the signal pattern which can identify the difference of 2 pixels or more.

  In the process of S4, if it is confirmed that the pixel position actually measured from the secondary electron image and the pixel position determined by the design match by matching the color PCi and the color PCth, this pass The pixel 104 at the inter-first position is set as the inter-pass start position.

  FIG. 5 shows a case where there is no displacement and the pixel position actually measured from the secondary electron image matches the pixel position determined by design.

  FIG. 5A shows a signal pattern calculated from the design at the electron gun boundary 401. The color PCth of the pixel 104 at the inter-pass head position is calculated based on the design data from the color PCo of the pixel 101 at the panel head position. Here, for example, the color PCth is shown in white.

  FIG. 5B shows a secondary electron image detected when there is no misalignment. The secondary electron image of the path 4 of the electron gun Xn is shown by a broken line on the left, and the path 1 of the electron gun Xn + 1. The secondary electron image is shown by the solid line on the right.

  Here, in the secondary electron image of pass 1 of the electron gun Xn + 1, the color PCi of the pixel 104 at the head position between passes is white, and the pixel position actually measured from the secondary electron image and the pixel position determined by design And match (S5).

  If the color PCi and the color PCth do not match in the step of S4, one of adjacent pixels is selected and adopted based on the barycentric position of the pixel (S6).

  In step S6, the positional relationship between the barycentric positions of the pixels is determined, and the barycentric position of the pixels actually measured from the secondary electron image is on the right side (on the electron gun Xn + 1 side) of the pixel position determined by design. In this case, it is determined that the secondary electron image is shifted to the right (electron gun Xn + 1 side), and the pixel on the left (electron gun Xn side) is adopted as the corresponding pixel. To do.

  In FIG. 6, the pixel position is shifted to the right (electron gun Xn + 1 side), and the pixel position actually measured from the secondary electron image is to the right (electron gun Xn + 1 side) from the pixel position determined by design. The case where it shifted | deviated is shown.

  FIG. 6A shows a signal pattern calculated from the design at the electron gun boundary 401, as in FIG. 5A. The color PCth of the pixel 104 at the inter-pass head position is calculated based on the design data from the color PCo of the pixel 101 at the panel head position. Here, for example, the color PCth is shown in white.

  6B and 6C show secondary electron images detected when the position is shifted to the right (electron gun Xn + 1 side), and the secondary electron image of the path 4 of the electron gun Xn is left. The secondary electron image of the path 1 of the electron gun Xn + 1 is indicated by a solid line on the right side. The secondary electron image of pass 1 of the electron gun Xn + 1 is shifted to the right beyond the electron gun boundary 401, and the colors PCi and PCth do not match. FIG. 6C shows a secondary electron image on the electron gun Xn side and a secondary electron image of the electron gun Xn + 1. In this case, the two secondary electron images cannot maintain continuity (S7).

  On the other hand, in step S6, the positional relationship between the barycentric positions of the pixels is determined, and the barycentric position of the pixels actually measured from the secondary electron image is on the left side (on the electron gun Xn side) from the pixel position determined by design In this case, it is determined that the secondary electron image is shifted to the left (electron gun Xn side), and the pixel on the right (electron gun Xn + 1 side) is adopted as the corresponding pixel. To do.

  FIG. 7 shows a case in which the position is shifted to the left (electron gun Xn side), and the pixel position measured from the secondary electron image is shifted to the left (electron gun Xn side) from the pixel position determined by design. Show.

  FIG. 7A shows a signal pattern calculated from the design at the electron gun boundary 401, as in FIG. The color PCth of the pixel 104 at the inter-pass head position is calculated based on the design data from the color PCo of the pixel 101 at the panel head position. Here, for example, the color PCth is shown in white.

  FIGS. 7B and 7C show secondary electron images detected when the position is shifted to the left (electron gun Xn side). The secondary electron image of the path 4 of the electron gun Xn is shown on the left side. The secondary electron image of the path 1 of the electron gun Xn + 1 is indicated by a solid line on the right side. The secondary electron image of pass 1 of the electron gun Xn + 1 is shifted to the left beyond the electron gun boundary 401, and the colors PCi and PCth do not match. FIG. 7C shows a secondary electron image on the electron gun Xn side and a secondary electron image of the electron gun Xn + 1. In this case, the two secondary electron images cannot maintain continuity (S8).

  In the steps S7 and S8, in order to employ adjacent pixels, each electron gun needs to be scanned with an overlapping range partially overlapping the range scanned by the adjacent electron gun.

  FIG. 8 is a diagram for explaining scanning having overlap. FIG. 8A shows a signal pattern calculated from the design at the electron gun boundary 401 as in FIG. The color PCth of the pixel 104 at the inter-pass head position is calculated based on the design data from the color PCo of the pixel 101 at the panel head position. Here, for example, the color PCth is shown in white.

  On the other hand, as shown in FIG. 8B, the electron gun Xn scans a part of the range of the electron gun Xn + 1 as an overlap range, and the electron gun Xn + 1 is shown in FIG. 8C. As described above, a part of the range of the electron gun Xn is scanned as an overlap range. By scanning with an overlapping range in this way, data of adjacent pixels can be acquired.

  Note that examples of inspection signals for forming a grid-like potential distribution, a stripe-like potential distribution on the panel, or the same potential distribution on the entire surface will be described with reference to FIGS.

  FIG. 9 is a diagram for explaining the relationship between the gate line and the source line of the panel. By applying inspection signals of a predetermined pattern to the gate lines and source lines of the panel, a grid-like potential distribution, a stripe-like potential distribution, or the same potential distribution can be formed on the entire surface.

  In FIG. 9, each pixel of the panel has an ITO electrode, each TFT is used as a switch element, and the voltage of the inspection signal is applied from the source line by the open / close control by the signal of the gate line. Here, the gate lines Go and the gate lines Ge are alternately wired, and the source lines So and the source lines Se are alternately wired.

  FIG. 10 shows an example of an inspection signal that forms a grid-like potential distribution. 10A and 10B show gate signals, and FIGS. 10C and 10D show source signals. 10A and 10B and the source signal shown in FIGS. 10C and 10D, a positive voltage (here, 10v) and a negative voltage in a grid pattern with respect to the pixels of the TFT array. (Here, −10 v) is applied alternately.

  The present invention can be applied to a liquid crystal array inspection device, an EB tester, a TFT and transistor inspection device, an organic EL array inspection device, a scanning electron microscope, a nondestructive inspection device, an array inspection device for a flat panel television, and the like. .

DESCRIPTION OF SYMBOLS 1 TFT array inspection apparatus 2 Inspection control circuit 3 Scan control circuit 4 Inspection signal application circuit 5 Stage 6 Electron beam source 7 Secondary electron detector 8 Signal processing unit 8a Detection circuit 8b Allocation unit 8c Normalization unit 8d Continuous processing unit 8e Data composition unit 8f Defective pixel detection unit 10 Substrate 101 Panel top pixel 104 Inter-pass first pixel 111 Inter-gun top pixel 200 Panel secondary electron image 201-204, 211-214 Inter-pass secondary electron image 301 Path boundary 302 Path boundary 303 Path boundary 401 Electron gun boundary Xn, Xn + 1 Electron gun

Claims (7)

In a TFT array inspection apparatus for inspecting a TFT array of a panel by detecting secondary electrons obtained by scanning an electron beam on a panel formed on a substrate,
A plurality of electron guns that irradiate a substrate with a plurality of electron beams;
A plurality of detectors for detecting a plurality of secondary electrons obtained by scanning each electron beam;
An inspection signal applying means for applying an inspection signal to the TFT array of the panel and forming a potential distribution of a predetermined pattern on the panel;
A plurality of secondary electron images obtained from detection signals of the plurality of detectors, and a signal processing unit that detects a defect of each pixel of the panel based on the secondary electron images,
The signal processing unit
In the plurality of secondary electron images, having a continuation processing unit that makes the boundary of adjacent secondary electron images continuous,
The continuation processing unit compares the signal pattern of the pixel at the end position of the secondary electron image with the signal pattern of the pixel corresponding to the end position calculated based on the pixel size from the end of the panel. And
A TFT array inspection apparatus characterized in that when the two signal patterns do not match, the boundary of adjacent secondary electron images is made continuous by shifting the secondary electron image by one pixel . Each of the electron guns scans an area obtained by dividing the panel,
The continuous processing unit includes:
2. The TFT array inspection apparatus according to claim 1, wherein, in the secondary electron image obtained in each of the divided regions, a boundary between secondary electron images of adjacent divided regions is made continuous. Each of the electron guns divides and scans each scanning area by a plurality of passes,
The continuous processing unit includes:
2. The TFT array inspection apparatus according to claim 1, wherein in the secondary electron image obtained in each pass, a boundary between secondary electron images in adjacent passes is made continuous. Each electron gun divides and scans the panel, and divides and scans each scanning area by a plurality of passes.
The continuous processing unit includes:
In the secondary electron image obtained in each pass, the boundary of the secondary electron image of the adjacent pass is made continuous,
2. The TFT array inspection apparatus according to claim 1, wherein, in the secondary electron image obtained in each of the divided regions, a boundary between secondary electron images of adjacent divided regions is made continuous. Test signal the test signal applying means is applied, characterized in that on the panel is a signal pattern forming a potential distribution grid pattern, TFT array inspection according to any one of claims 1 to 4 apparatus. A method of determining a coordinate position of a pixel included in a TFT array panel with respect to a substrate of the pixel,
Scan the electron beam in each divided area on the substrate,
Detecting a plurality of secondary electrons obtained by scanning the electron beam, and obtaining a secondary electron image for each region;
Performing a continuation process for making the boundaries of adjacent secondary electron images continuous for the plurality of secondary electron images;
The continuation processing compares the signal pattern of the pixel at the end position of the secondary electron image with the signal pattern of the pixel corresponding to the end position calculated based on the pixel size from the end of the panel. ,
If the two signal patterns do not match, the boundary of adjacent secondary electron images is made continuous by shifting the secondary electron image by one pixel,
A pixel coordinate position determination method, wherein a coordinate position of a pixel of the secondary electron image subjected to the continuous processing is determined as a coordinate position of a pixel of the panel. An inspection signal of a signal pattern that forms a potential distribution of a grid pattern on the panel is applied to the TFT array of the panel to form a potential distribution of the grid pattern on the panel,
7. The pixel coordinate position determining method according to claim 6 , wherein a secondary electron image is obtained by scanning an electron beam in each region of the substrate on which the potential distribution of the grid pattern is formed.