A graphical output method and system for measurement results

Abstract

The present invention discloses a method and system for graphically outputting measurement results, comprising: obtaining a first measurement result of the scanned image based on a preset first measurement parameter; extracting a first grayscale extreme point and a second grayscale extreme point corresponding to the scanned image according to a grayscale value distribution cross-sectional diagram of the scanned image and the first measurement parameter to calculate a second measurement result corresponding to the scanned image; obtaining a difference between the first measurement result and the second measurement result to update the first grayscale extreme point and the second grayscale extreme point according to the difference to obtain a third grayscale extreme point and a fourth grayscale extreme point; updating the first measurement parameter according to the third grayscale extreme point and the fourth grayscale extreme point to extract a third measurement result of the scanned image according to the updated first measurement parameter, and generating a digitized image corresponding to the third measurement result to improve the accuracy of the digitized graphic.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a method and system for graphically outputting measurement results. Background Art

[0002] The photolithography process transfers the pattern on the photomask to the wafer through the principle of photochemical reaction. It is the prerequisite for subsequent etching and ion implantation at specific locations. Therefore, ensuring the accuracy of photolithography is the key to wafer manufacturing.

[0003] Measurement technology can monitor and measure wafer quality in wafer manufacturing. CDSEM has gradually become a measurement technology used in semiconductor manufacturing because it can measure the size of fine patterns formed on semiconductor wafers. It is especially used as a means of measuring CD (critical dimension) after photolithography and etching processes.

[0004] However, the current CDSEM measurement results can only output numerical results and measurement images, and cannot be further digitized and analyzed. In addition, the subsequent image extraction technology has differences in the recipes established for different measurement parameters, and cannot correctly reflect the online measurement results, resulting in the graphical accuracy of the measurement results not meeting expectations. Summary of the invention

[0005] In order to solve the above technical problems, the present invention discloses a method and system for graphical output of measurement results, which are used to improve the accuracy of graphical output of measurement results.

[0006] In order to achieve the above object, the present invention discloses a method for graphically outputting measurement results, comprising:

[0007] Acquire a scanned image corresponding to the sample to be tested under a microscope, and obtain a first measurement result of the scanned image based on a preset first measurement parameter;

[0008] Acquire a grayscale value distribution cross-sectional diagram of the scanned image, and extract a first grayscale extreme value point and a second grayscale extreme value point corresponding to the scanned image according to the grayscale value distribution cross-sectional diagram and the first measurement parameter;

[0009] Calculate a second measurement result corresponding to the scanned image according to the first grayscale extreme value point and the second grayscale extreme value point;

[0010] Obtaining a difference between the first measurement result and the second measurement result, so as to update the first grayscale extreme value point and the second grayscale extreme value point according to the difference, and obtain a third grayscale extreme value point and a fourth grayscale extreme value point;

[0011] The first measurement parameter is updated according to the third grayscale extreme value point and the fourth grayscale extreme value point, so as to extract a third measurement result of the scanned image according to the updated first measurement parameter, and generate a digitized image corresponding to the third measurement result.

[0012] The present invention discloses a method for graphically outputting measurement results. First, a scanning image corresponding to a sample to be measured under a microscope is obtained, and a first measurement result is generated after the scanning image is measured according to a preset first measurement parameter, so as to provide a matching basis for subsequent extraction of extreme points in the image according to the first measurement result, so as to achieve matching between the measurement parameters used in image processing and the first measurement parameters, thereby improving the accuracy of graphical measurement results. In the process of parameter matching in image processing technology, the first extreme point and the second extreme point are first selected based on the gray value distribution cross-sectional diagram of the scanning image and the first measurement parameter, and the image processing and image measurement are compared with less data to improve the efficiency of graphical measurement. Furthermore, based on the comparison result, the extreme point is continuously updated until the size of the extreme point is close to the measured size. At this time, the measurement parameter is updated based on the update of the extreme point, and the parameter matching between image processing and measurement is completed. The measurement result is graphically measured using the updated measurement parameter to ensure the accuracy of graphical measurement.

[0013] As a preferred example, the step of acquiring a scanned image corresponding to the sample to be tested under a microscope and obtaining a first size of the scanned image based on a preset first measurement parameter includes:

[0014] Obtaining a CDSEM image corresponding to the sample to be tested;

[0015] The CDSEM image is measured based on preset CDSEM measurement parameters to obtain a first CD value corresponding to the CDSEM image; wherein the CDSEM measurement parameters are set as a gray value interval.

[0016] The present invention obtains a CDSEM image of a sample to be tested to measure a critical dimension, and simultaneously obtains CDSEM measurement parameters to subsequently screen pixel points of the image according to the CDSEM measurement parameters, thereby improving the efficiency of graphics.

[0017] As a preferred example, extracting the first grayscale extreme value point and the second grayscale extreme value point corresponding to the scanned image according to the grayscale value distribution cross-sectional diagram and the first measurement parameter includes:

[0018] Acquire the two-dimensional coordinates of each pixel point from the gray value distribution cross-sectional diagram; wherein the two-dimensional coordinates include pixel coordinates and gray value;

[0019] According to the grayscale value and the pixel coordinates, a plurality of grayscale extreme value points are screened out from the plurality of pixel points by a preset Newton algorithm;

[0020] From the plurality of grayscale extreme value points, a first grayscale extreme value point and a second grayscale extreme value point corresponding to the grayscale value within the grayscale value interval are screened.

[0021] Based on the grayscale value interval and the grayscale extreme point extraction method, the present invention obtains grayscale extreme points from the scanned image to achieve matching of image processing parameters with measurement parameters, realizes parameter matching using less data, and improves the efficiency of graphical measurement results.

[0022] As a preferred example, the calculation expression of the Newton algorithm is:

[0023]

[0024]

[0025] Wherein, k_1 and k_2 represent the first slope and the second slope; f(x_2) represents the first pixel point with coordinate x_2; f(x_1) represents the second pixel point with coordinate x_1 before f(x_2); f(x_3) represents the third pixel point with coordinate x_3 after f(x_2);

[0026] Comparing the first slope and the second slope with a preset slope threshold respectively;

[0027] When the first slope is greater than the slope threshold and the second slope is less than the slope threshold or the first slope is less than the slope threshold and the second slope is greater than the slope threshold, the first pixel point is determined to be an extreme point.

[0028] The present invention uses Newton's method to find the extreme point position, ensures the accuracy of extreme point screening, and then ensures the accuracy of measurement result graphics based on precise extreme points. At the same time, the screened extreme points are used to match parameters, thereby reducing the amount of data processing and improving the efficiency of visualization.

[0029] As a preferred example, the calculating the second measurement result corresponding to the scanned image according to the first grayscale extreme value point and the second grayscale extreme value point includes:

[0030] Acquire a first two-dimensional coordinate corresponding to the first grayscale extreme value point and a second two-dimensional coordinate corresponding to the second grayscale extreme value point from the grayscale value distribution cross-sectional diagram;

[0031] According to the first two-dimensional coordinates and the second two-dimensional coordinates, the distance between the first grayscale extreme value point and the second grayscale extreme value point is calculated, and the distance is determined as the second CD value corresponding to the scanned image.

[0032] The present invention calculates the CD value corresponding to the cross section according to the coordinates of the selected extreme value points, and compares the CD value with the CD value in the measurement result, so as to update the measurement parameters according to the comparison result and improve the accuracy of the graphics.

[0033] As a preferred example, obtaining a difference between the first measurement result and the second measurement result to update the first grayscale extreme point and the second grayscale extreme point according to the difference to obtain a third grayscale extreme point and a fourth grayscale extreme point includes:

[0034] Obtaining a difference between the first CD value and the second CD value and obtaining a comparison result between the first CD value and the second CD value;

[0035] When the difference is not within the preset tolerance threshold range and the second CD value is greater than the first CD value, in the gray value distribution cross-sectional diagram, the pixel point coordinates based on the first gray value extreme point are moved to the right and the pixel point coordinates based on the second gray value extreme point are moved to the left;

[0036] When the difference is not within the preset tolerance threshold range and the second CD value is less than the first CD value, in the gray value distribution cross-sectional diagram, the pixel point coordinates based on the first gray value extreme point are moved to the left and the pixel point coordinates based on the second gray value extreme point are moved to the right;

[0037] When the difference between the CD values ​​corresponding to the first pixel point and the second pixel point obtained after the movement and the first CD value is within the tolerance threshold range, the first pixel point is determined to be the third grayscale extreme point and the second pixel point is determined to be the fourth grayscale extreme point.

[0038] When updating the extreme value point, the present invention utilizes the comparison result between the CD and the first CD value of the measurement result to sequentially screen the extreme value points, thereby improving the efficiency of graphics.

[0039] As a preferred example, the updating of the first measurement parameter according to the third grayscale extreme value point and the fourth grayscale extreme value point includes:

[0040] Obtaining a grayscale difference between the third grayscale extreme value point and the first grayscale extreme value point or obtaining a grayscale difference between the fourth grayscale extreme value point and the second grayscale extreme value point;

[0041] Calculate the percentage of the grayscale difference to the grayscale value of the first grayscale extreme value point or to the grayscale value of the second grayscale extreme value point;

[0042] The percentage is determined as the updated first measurement parameter.

[0043] The present invention updates the measurement parameters by utilizing the percentage of the grayscale change when the extreme point is updated to the grayscale value of the initial extreme point, so that the updated measurement parameters adapt to the image processing technology, while ensuring the matching of the image processing and the measured parameters, and ensuring the accuracy of the graphical measurement results.

[0044] As a preferred example, the step of extracting the third measurement result of the scanned image according to the updated first measurement parameter and generating a digitized image corresponding to the third measurement result includes:

[0045] Extracting a third grayscale extreme value point and a fourth grayscale extreme value point in each grayscale value distribution cross-sectional diagram in the scanned image according to the updated first measurement parameter;

[0046] Connecting all the third grayscale extreme value points to form a first measurement edge;

[0047] Connecting all of the fourth grayscale extreme value points to form a second measurement edge;

[0048] A corresponding digitized image is generated based on the first measured edge, the second measured edge, and the scanned image.

[0049] The present invention connects the third grayscale extreme point and the fourth grayscale extreme point of each cross section, thereby generating two edges in the image, and the size between the two edges is infinitely close to the first CD value, thereby generating a digitized graph of the measurement result through the two edges and the scanned image.

[0050] On the other hand, the present invention discloses a graphical output system for measurement results, the system comprising a first measurement module, an extreme point extraction module, a second measurement module, an extreme point update module and a measurement graphical module;

[0051] The first measurement module is used to collect a scanned image corresponding to the sample to be measured under a microscope, and obtain a first measurement result of the scanned image based on a preset first measurement parameter;

[0052] The extreme value point extraction module is used to obtain a gray value distribution cross-sectional diagram of the scanned image, so as to extract a first gray value extreme value point and a second gray value extreme value point corresponding to the scanned image according to the gray value distribution cross-sectional diagram and the first measurement parameter;

[0053] The second measurement module is used to calculate a second measurement result corresponding to the scanned image according to the first grayscale extreme value point and the second grayscale extreme value point;

[0054] The extreme value point updating module is used to obtain the difference between the first measurement result and the second measurement result, so as to update the first grayscale extreme value point and the second grayscale extreme value point according to the difference, and obtain the third grayscale extreme value point and the fourth grayscale extreme value point;

[0055] The measurement graphical module is used to update the first measurement parameter according to the third grayscale extreme point and the fourth grayscale extreme point, so as to extract a third measurement result of the scanned image according to the updated first measurement parameter and generate a digitized image corresponding to the third measurement result.

[0056] The present invention discloses a graphical output system for measurement results. First, a scanning image corresponding to a sample to be measured under a microscope is obtained, and a first measurement result is generated after the scanning image is measured according to a preset first measurement parameter, so as to provide a matching basis for subsequent extraction of extreme points in the image according to the first measurement result, so as to achieve matching between the measurement parameters used in image processing and the first measurement parameters, thereby improving the accuracy of the graphical output of the measurement results. In the process of parameter matching in the image processing technology, the first extreme point and the second extreme point are first selected based on the gray value distribution cross-sectional diagram of the scanning image and the first measurement parameter, and the image processing and image measurement are compared with less data to improve the efficiency of the graphical output. Furthermore, based on the comparison result, the extreme point is continuously updated until the size of the extreme point is close to the measured size. At this time, the measurement parameter is updated based on the update of the extreme point, and the parameter matching between the image processing and the measurement is completed. The measurement result is graphically displayed using the updated measurement parameter to ensure the accuracy of the graphical output.

[0057] As a preferred example, the first measurement module includes a scanning unit and a measurement unit;

[0058] The scanning unit is used to obtain a CDSEM image corresponding to the sample to be tested;

[0059] The measuring unit is used to measure the CDSEM image based on preset CDSEM measurement parameters to obtain a first CD value corresponding to the CDSEM image; wherein the CDSEM measurement parameters are set as a gray value interval.

[0060] The present invention obtains a CDSEM image of a sample to be tested to measure a critical dimension, and simultaneously obtains CDSEM measurement parameters to subsequently screen pixel points of the image according to the CDSEM measurement parameters, thereby improving the efficiency of graphics. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 : A schematic diagram of a flow chart of a method for graphically outputting measurement results disclosed in an embodiment of the present invention;

[0062] Figure 2 : is a structural diagram of a graphical output system for measurement results disclosed in an embodiment of the present invention;

[0063] Figure 3 : A flowchart of a method for graphically outputting measurement results disclosed in another embodiment of the present invention;

[0064] Figure 4 : A grayscale value distribution cross-sectional diagram disclosed in yet another embodiment of the present invention. DETAILED DESCRIPTION

[0065] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] Embodiment 1

[0067] This embodiment discloses a graphical output method for measurement results. For the specific implementation process of the output method, please refer to Figure 1 , mainly including steps 101 to 105, wherein the steps are mainly:

[0068] Step 101: Acquire a scanned image corresponding to a sample to be tested under a microscope, and obtain a first measurement result of the scanned image based on a preset first measurement parameter;

[0069] In this embodiment, this step mainly includes: obtaining a CDSEM image corresponding to the sample to be tested; measuring the CDSEM image based on preset CDSEM measurement parameters to obtain a first CD value corresponding to the CDSEM image; wherein the CDSEM measurement parameters are set as a grayscale value interval.

[0070] In this embodiment, this step obtains a CDSEM image of the sample to be tested to measure the critical dimension, and simultaneously obtains the measured CDSEM measurement parameters, so that the pixel points of the image can be subsequently screened according to the CDSEM measurement parameters to improve the efficiency of graphics.

[0071] Step 102: Obtain a grayscale value distribution cross-sectional diagram of the scanned image, and extract a first grayscale extreme value point and a second grayscale extreme value point corresponding to the scanned image according to the grayscale value distribution cross-sectional diagram and the first measurement parameter.

[0072] In this embodiment, this step mainly includes: obtaining the two-dimensional coordinates of each pixel point from the grayscale value distribution cross-sectional diagram; wherein the two-dimensional coordinates include pixel coordinates and grayscale values; based on the grayscale values ​​and the pixel coordinates, screening out a number of grayscale extreme points from a number of the pixel points through a preset Newton algorithm; from the number of the grayscale extreme points, screening out the first grayscale extreme point and the second grayscale extreme point corresponding to the grayscale value within the grayscale value range.

[0073] Furthermore, the calculation expression of the Newton algorithm is:

[0074]

[0075]

[0076] Wherein, k_1 and k_2 represent the first slope and the second slope; f(x_2) represents the first pixel point with coordinate x_2; f(x_1) represents the second pixel point with coordinate x_1 before f(x_2); f(x_3) represents the third pixel point with coordinate x_3 after f(x_2);

[0077] Comparing the first slope and the second slope with a preset slope threshold respectively;

[0078] When the first slope is greater than the slope threshold and the second slope is less than the slope threshold or the first slope is less than the slope threshold and the second slope is greater than the slope threshold, the first pixel point is determined to be an extreme point.

[0079] In this embodiment, this step is based on the gray value interval and the gray extreme point extraction method, and gray extreme points are obtained from the scanned image to achieve matching of image processing parameters and measurement parameters, thereby achieving parameter matching using less data and improving the efficiency of graphical measurement results. Furthermore, by using Newton's method to find the extreme point position, the accuracy of extreme point screening is guaranteed, and then the accuracy of graphical measurement results is guaranteed based on the precise extreme points, and at the same time, the selected extreme points are used to match parameters, reducing the amount of data processing and improving the efficiency of imaging.

[0080] Step 103: Calculate a second measurement result corresponding to the scanned image according to the first grayscale extreme value point and the second grayscale extreme value point.

[0081] In this embodiment, this step mainly includes: obtaining the first two-dimensional coordinates corresponding to the first grayscale extreme point and the second two-dimensional coordinates corresponding to the second grayscale extreme point from the grayscale value distribution cross-sectional diagram; calculating the distance between the first grayscale extreme point and the second grayscale extreme point based on the first two-dimensional coordinates and the second two-dimensional coordinates, and determining the distance as the second CD value corresponding to the scanned image.

[0082] In this embodiment, this step calculates the CD value corresponding to the cross section according to the coordinates of the selected extreme point, and compares the CD value with the CD value in the measurement result, so as to update the measurement parameters according to the comparison result and improve the accuracy of the graphics.

[0083] Step 104: Obtain a difference between the first measurement result and the second measurement result, and update the first grayscale extreme value point and the second grayscale extreme value point according to the difference to obtain a third grayscale extreme value point and a fourth grayscale extreme value point.

[0084] In this embodiment, this step mainly includes: obtaining the difference between the first CD value and the second CD value and obtaining the comparison result of the first CD value and the second CD value; when the difference is not within the preset tolerance threshold range and the second CD value is greater than the first CD value, in the grayscale value distribution cross-sectional diagram, the pixel coordinates based on the first grayscale extreme value point are moved to the right and the pixel coordinates based on the second grayscale extreme value point are moved to the left; when the difference is not within the preset tolerance threshold range and the second CD value is less than the first CD value, in the grayscale value distribution cross-sectional diagram, the pixel coordinates based on the first grayscale extreme value point are moved to the left and the pixel coordinates based on the second grayscale extreme value point are moved to the right; when the difference between the CD values ​​corresponding to the first pixel and the second pixel obtained after the movement and the first CD value is within the tolerance threshold range, the first pixel is determined to be the third grayscale extreme value point and the second pixel is determined to be the fourth grayscale extreme value point.

[0085] In this embodiment, when updating the extreme value point, this step uses the comparison result between the CD and the first CD value of the measurement result to sequentially screen the extreme value points, thereby improving the efficiency of graphics.

[0086] Step 105: Update the first measurement parameter according to the third grayscale extreme point and the fourth grayscale extreme point, so as to extract a third measurement result of the scanned image according to the updated first measurement parameter, and generate a digitized image corresponding to the third measurement result.

[0087] In this embodiment, this step mainly includes: obtaining the grayscale difference between the third grayscale extreme point and the first grayscale extreme point, or obtaining the grayscale difference between the fourth grayscale extreme point and the second grayscale extreme point; calculating the percentage of the grayscale difference to the grayscale value of the first grayscale extreme point or the grayscale value of the second grayscale extreme point; and determining the percentage as the updated first measurement parameter.

[0088] Furthermore, the third grayscale extreme point and the fourth grayscale extreme point in each grayscale value distribution cross-sectional diagram in the scanned image are extracted according to the updated first measurement parameter; all the third grayscale extreme points are connected to form a first measurement edge; all the fourth grayscale extreme points are connected to form a second measurement edge; and based on the first measurement edge, the second measurement edge and the scanned image, a corresponding digitized image is generated.

[0089] In this embodiment, this step updates the measurement parameters by using the percentage of the grayscale change when the extreme point is updated to the grayscale value of the initial extreme point, so that the updated measurement parameters adapt to the image processing technology, while ensuring the matching of the image processing and the measured parameters, and ensuring the accuracy of the graphical measurement results. Further, by connecting the third grayscale extreme point and the fourth grayscale extreme point of each cross section, two edges in the image are generated, and the size between the two edges is infinitely close to the first CD value, so that the digital graphics of the measurement results can be generated through the two edges and the scanned image.

[0090] On the other hand, this embodiment discloses a graphical output system for measurement results. For the specific structure of the output system, please refer to Figure 2 , including a first measurement module 201, an extreme point extraction module 202, a second measurement module 203, an extreme point update module 204 and a measurement graphics module 205.

[0091] The first measurement module 201 is used to collect a scanned image corresponding to the sample to be measured under a microscope, and obtain a first measurement result of the scanned image based on a preset first measurement parameter.

[0092] The extreme value point extraction module 202 is used to obtain a gray value distribution cross-sectional diagram of the scanned image, so as to extract a first gray value extreme value point and a second gray value extreme value point corresponding to the scanned image according to the gray value distribution cross-sectional diagram and the first measurement parameter.

[0093] The second measurement module 203 is used to calculate a second measurement result corresponding to the scanned image according to the first grayscale extreme value point and the second grayscale extreme value point.

[0094] The extreme value point updating module 204 is used to obtain the difference between the first measurement result and the second measurement result, so as to update the first grayscale extreme value point and the second grayscale extreme value point according to the difference, and obtain the third grayscale extreme value point and the fourth grayscale extreme value point.

[0095] The measurement graphical module 205 is used to update the first measurement parameter according to the third grayscale extreme point and the fourth grayscale extreme point, so as to extract the third measurement result of the scanned image according to the updated first measurement parameter and generate a digitized image corresponding to the third measurement result.

[0096] In this embodiment, the first measuring module 201 includes a scanning unit and a measuring unit.

[0097] The scanning unit is used to obtain the CDSEM image corresponding to the sample to be tested.

[0098] The measuring unit is used to measure the CDSEM image based on preset CDSEM measurement parameters to obtain a first CD value corresponding to the CDSEM image; wherein the CDSEM measurement parameters are set as a gray value interval.

[0099] In this embodiment, the extreme value extraction module 202 includes a data acquisition unit and a screening unit.

[0100] The data acquisition unit is used to acquire the two-dimensional coordinates of each pixel point from the gray value distribution cross-sectional diagram; wherein the two-dimensional coordinates include pixel coordinates and gray values.

[0101] The screening unit is used to screen out a plurality of grayscale extreme value points from the plurality of pixel points according to the grayscale value and the pixel coordinates by a preset Newton algorithm; and to screen out a first grayscale extreme value point and a second grayscale extreme value point corresponding to the grayscale value within the grayscale value interval from the plurality of grayscale extreme value points.

[0102] In this embodiment, the second measurement module includes a coordinate unit and a calculation unit.

[0103] The coordinate unit is used to obtain the first two-dimensional coordinates corresponding to the first grayscale extreme value point and the second two-dimensional coordinates corresponding to the second grayscale extreme value point from the grayscale value distribution cross-sectional diagram.

[0104] The calculation unit is used to calculate the distance between the first grayscale extreme value point and the second grayscale extreme value point according to the first two-dimensional coordinates and the second two-dimensional coordinates, and determine the distance as the second CD value corresponding to the scanned image.

[0105] The present embodiment discloses a method and system for graphical output of measurement results. First, a scanned image corresponding to a sample to be measured under a microscope is obtained, and a first size is generated after the scanned image is measured according to a preset first measurement parameter, so as to provide a matching basis for subsequent extraction of extreme points in the image according to the first size, so as to achieve matching between the measurement parameters used in image processing and the first measurement parameters, thereby improving the accuracy of the graphical output of the results on both sides. In the process of parameter matching in the image processing technology, the first extreme point and the second extreme point are first selected based on the gray value distribution cross-sectional diagram of the scanned image and the first measurement parameter, and the image processing and image measurement are compared with less data to improve the efficiency of the graphical output. Furthermore, based on the comparison result, the extreme point is continuously updated until the size of the extreme point is consistent with the measured size. At this time, the measurement parameter is updated based on the update of the extreme point, and the parameter matching of the image processing and the measurement is completed. The measurement result is graphically displayed using the updated measurement parameter to ensure the accuracy of the graphical output.

[0106] Embodiment 2

[0107] This embodiment further discloses a graphical output method based on measurement results, wherein the output method performs image processing on the sample to be measured through an online CDSEM recipe, obtains a CDSEM image corresponding to the sample to be measured and a measurement result corresponding to the CDSEM image, and graphically converts the measurement result through a preset image extraction technology. For details, please refer to the implementation process of the graphical output method. Figure 3 , mainly including steps 301 to 305, wherein the steps are mainly:

[0108] Step 301: Obtain a CDSEM image corresponding to a sample to be tested, a CDSEM measurement result corresponding to the CDSEM image, and a CDSEM recipe parameter corresponding to the measurement result.

[0109] In this embodiment, the step mainly includes: measuring the CDSEM image obtained by scanning based on the CDSEM technology with preset CDSEM recipe parameters, and obtaining a first measurement result corresponding to the scanned image, that is, a first CD value (critical dimension). The CDSEM recipe parameter (threshold) is a parameter that limits the edge grabbing range, and is used to distinguish the edges corresponding to different areas with different grayscale value ranges in the image. For example, when the CDSEMrecipe parameter is set to 120-250, when the edge is grabbed according to the CDSEM recipe parameter, the grayscale value corresponding to the corresponding measured edge is within the range of 120-250.

[0110] Furthermore, the CDSEM image is essentially a two-dimensional grayscale value matrix. Specifically, Figure 4 The line graph shown is a one-dimensional grayscale value distribution diagram corresponding to a cross section of the CDSEM image along one direction. Figure 4 The line graph shown can clearly show the extreme points and obtain the CD value of each position. According to this method, the CD of all cross sections can be obtained, thereby obtaining the edge capture image of the CDSEM image based on the first critical dimension.

[0111] Step 302: Obtain a gray value distribution cross-sectional diagram of the CDSEM image, and extract the corresponding first and second extreme value points based on the CDSEM recipe parameters and the preset edge grabbing options.

[0112] In this embodiment, the step mainly includes: obtaining a plurality of grayscale extreme value points from the grayscale value distribution cross-sectional diagram, and then screening out a first grayscale extreme value point and a second grayscale extreme value point from the grayscale extreme value points according to the CDSEM recipe parameters.

[0113] Specifically, at least one grayscale value distribution cross-sectional diagram is extracted from the CDSEM image, and then a preset Newton algorithm is used to extract a number of corresponding grayscale extreme value points in the grayscale value distribution cross-sectional diagram.

[0114] Specifically, refer to Figure 4 As shown in the gray value distribution cross-sectional diagram, the gray value distribution cross-sectional diagram includes the pixel coordinates and gray value of each pixel point, and whether each pixel point is a gray extreme point is determined by a preset Newton algorithm. Specifically, when the gray extreme point is extracted by the Newton algorithm, the calculation expression of the Newton algorithm is:

[0115]

[0116]

[0117] Among them, k_1 and k_2 represent the first slope and the second slope; f(x_2) represents the first pixel point with coordinates x_2; f(x_1) represents the second pixel point with coordinates x_1 before f(x_2); f(x_3) represents the third pixel point with coordinates x_3 after f(x_2). .

[0118] Specifically, refer to Figure 4, A, B, C, D, E, and F are grayscale extreme value points extracted by Newton algorithm. Referring to the CDSEM recipe parameters provided in the above steps, the first grayscale extreme value point and the second grayscale extreme value point for parameter matching are screened out from the grayscale extreme value points.

[0119] Optionally, the corresponding extreme points are captured based on the preset edge capture options Top, Middle, Bottom and the CDSEM recipe parameters. Wherein, the TOP, Middle, Bottom are the names for the image measurement of a general trapezoidal cross section. Specifically, Figure 4 As mentioned above, TOP usually grabs the distance between the extreme points with the largest grayscale values, which is regarded as the CD value at the top of the trapezoidal figure. Generally, the grayscale value of 110~200 is defined as the TOP CD range; bottom usually grabs the distance between the extreme points with the smallest grayscale values, which is regarded as the CD value at the bottom of the trapezoidal figure. Generally, the grayscale value of 25~50 is defined as the bottom CD range; and middle is a range between the maximum extreme point and the minimum extreme point as the middle, and the grayscale value of 75~105 is generally defined as the middle CD range. TOP, Middle, and Bottom can be regarded as the relative size of the grayscale value.

[0120] Reference Figure 4 When the threshold is selected within the grayscale value range of 120 to 250 for edge grabbing, the extreme points obtained by the screening are extreme point A and extreme point B, which correspond to the first grayscale extreme point and the second grayscale extreme point.

[0121] Step 303: Obtain the distance between the first extreme point and the second extreme point, and determine whether the distance is consistent with the CDSEM measurement result.

[0122] Specifically, in this embodiment, refer to Figure 4 The CD value is actually the distance between the two extreme points. The vertical axis of the line graph is the gray value, and the horizontal axis is the position of the pixel. Each pixel corresponds to 1nm. The CD value can be obtained by subtracting the horizontal axes of the two extreme points.

[0123] The CD value is compared with the CD value in the CDSEM measurement result to determine whether they are consistent.

[0124] Step 304: When there is inconsistency, the first extreme point and the second extreme point are updated until the distance between the third extreme point and the fourth extreme point obtained after the update is consistent with the CDSEM measurement result.

[0125] In this embodiment, this step mainly includes: updating the first extreme value point and the second extreme value point to be the third extreme value point and the fourth extreme value point according to the second CD value and the first CD value.

[0126] Specifically, in this embodiment, when the CD values ​​of the first extreme point and the second extreme point are larger than the CDSEM measurement value, the search continues to the inside of the extreme point until the CD value of the image extraction edge is consistent with the CDSEM measurement value. When the CD value of the image extraction is smaller than the CDSEM measurement value, the search continues to the outside of the extreme point until the CD value of the image extraction edge is consistent with the CDSEM measurement value. Among them, taking the two extreme points A (left point) and the extreme point B (right point) as the reference, if the image capture CD value is larger than the CDSEM measurement value, it means that the intercepts of the extreme points A and B are too large. At this time, for the extreme point A, it is necessary to find the point C with a smaller gray value corresponding to the extreme point A to the right (such as 1% smaller), and similarly, for the extreme point B, it is necessary to find the point D with a smaller gray value corresponding to the extreme point B to the left (such as 1% smaller). At this time, the line connecting the points C and D will be smaller than AB. Through multiple iterations, it is always possible to find the line connecting the points C and D that meets the CDSEM measurement value.

[0127] Step 305: Update the CDSEM recipe parameters according to the third extreme point and the fourth extreme point, so as to generate a digitized graph of the CDSEM measurement result according to the updated CDSEM recipe parameters.

[0128] In this embodiment, the step mainly includes: updating the first measurement parameter to the second measurement parameter according to the third extreme point and the fourth extreme point, and extracting the third extreme point and the fourth extreme point of each of the first gray value distribution cross-section diagrams in the scanned image based on the second measurement parameter; and generating a digitized graph corresponding to the first CD value according to the third extreme point and the fourth extreme point.

[0129] Specifically, when the CD values ​​of the third extreme point and the fourth extreme point are consistent with the CDSEM measurement values, it is confirmed that the grayscale values ​​of points C and D are 5% smaller than the grayscale values ​​of extreme points A and B, and 5% is saved as the second measurement parameter threshold.

[0130] Based on the second measurement parameter, capture the C point and the D point of each section in the CDSEM image, connect the C point and the D point of all sections to obtain two edges, and generate the corresponding GDS file, i.e., the digital graphic, through the layout tool or the OPC manufacturer's related tools.

[0131] Compared with the CDSEM machine, the graphical output method of the measurement results disclosed in this embodiment can process data and debug recipes offline in large quantities, without occupying the machine and CDSEM server, thus improving efficiency. Furthermore, compared with the CDSEM output image results, the digital graphics can obtain more measurement details and realize measurement of any position of the graphics. In the Optical Proximity Correction (OPC) group model establishment, manual weight measurement of abnormal data is required. This technology can realize automatic weight measurement and reduce the workload of engineers.

[0132] Furthermore, ordinary CDSEM measurement can only have one measurement value and cannot obtain more information. OPC model prediction can generate digital graphics in GDS or OAS format. The advantage of digital graphics is that more details can be obtained and each position of the graphics can be measured. In this embodiment, by matching the results of online measurement and generating corresponding digital graphics, the digital graphics generated by the OPC model and the digital graphics generated by matching measurement are superimposed to more intuitively see the difference between the OPC model prediction and the actual measurement, and better evaluate the prediction ability of the model.

[0133] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for graphically outputting measurement results, characterized in that: include: Acquire a scanned image corresponding to the sample to be tested under a microscope, and obtain a first measurement result of the scanned image based on a preset first measurement parameter; Acquire a grayscale value distribution cross-sectional diagram of the scanned image, and extract a first grayscale extreme value point and a second grayscale extreme value point corresponding to the scanned image according to the grayscale value distribution cross-sectional diagram and the first measurement parameter; Calculate a second measurement result corresponding to the scanned image according to the first grayscale extreme value point and the second grayscale extreme value point; Obtaining a difference between the first measurement result and the second measurement result, so as to update the first grayscale extreme value point and the second grayscale extreme value point according to the difference, and obtain a third grayscale extreme value point and a fourth grayscale extreme value point; The first measurement parameter is updated according to the third grayscale extreme value point and the fourth grayscale extreme value point, so as to extract a third measurement result of the scanned image according to the updated first measurement parameter, and generate a digitized image corresponding to the third measurement result.

2. The method for graphically outputting measurement results according to claim 1, characterized in that: The step of acquiring a scanned image corresponding to the sample to be tested under a microscope and obtaining a first size of the scanned image based on a preset first measurement parameter includes: Obtaining a CDSEM image corresponding to the sample to be tested; The CDSEM image is measured based on preset CDSEM measurement parameters to obtain a first CD value corresponding to the CDSEM image; wherein the CDSEM measurement parameters are set as a gray value interval.

3. The method for graphically outputting measurement results according to claim 2, characterized in that: The step of extracting the first grayscale extreme value point and the second grayscale extreme value point corresponding to the scanned image according to the grayscale value distribution cross-sectional diagram and the first measurement parameter comprises: Acquire the two-dimensional coordinates of each pixel point from the gray value distribution cross-sectional diagram; wherein the two-dimensional coordinates include pixel coordinates and gray value; According to the grayscale value and the pixel coordinates, a plurality of grayscale extreme value points are selected from the plurality of pixel points by a preset Newton algorithm; From the plurality of grayscale extreme value points, a first grayscale extreme value point and a second grayscale extreme value point corresponding to the grayscale value within the grayscale value interval are screened.

4. The method for graphically outputting measurement results according to claim 3, characterized in that: The calculation expression of the Newton algorithm is: Wherein, k_1 and k_2 represent the first slope and the second slope; f(x_2) represents the first pixel point with coordinate x_2; f(x_1) represents the second pixel point with coordinate x_1 before f(x_2); f(x_3) represents the third pixel point with coordinate x_3 after f(x_2); Comparing the first slope and the second slope with a preset slope threshold respectively; When the first slope is greater than the slope threshold and the second slope is less than the slope threshold or the first slope is less than the slope threshold and the second slope is greater than the slope threshold, the first pixel point is determined to be an extreme point.

5. The method for graphically outputting measurement results according to claim 1, characterized in that: The calculating a second measurement result corresponding to the scanned image according to the first grayscale extreme value point and the second grayscale extreme value point includes: Acquire a first two-dimensional coordinate corresponding to the first grayscale extreme value point and a second two-dimensional coordinate corresponding to the second grayscale extreme value point from the grayscale value distribution cross-sectional diagram; According to the first two-dimensional coordinates and the second two-dimensional coordinates, the distance between the first grayscale extreme value point and the second grayscale extreme value point is calculated, and the distance is determined as the second CD value corresponding to the scanned image.

6. A graphical output method of measurement results according to any one of claims 2 to 5, characterized in that: The obtaining of the difference between the first measurement result and the second measurement result, and updating the first grayscale extreme value point and the second grayscale extreme value point according to the difference, to obtain the third grayscale extreme value point and the fourth grayscale extreme value point, comprises: Obtaining a difference between a first CD value and a second CD value and obtaining a comparison result between the first CD value and the second CD value; When the difference is not within the preset tolerance threshold range and the second CD value is greater than the first CD value, in the gray value distribution cross-sectional diagram, the pixel point coordinates based on the first gray value extreme point are moved to the right and the pixel point coordinates based on the second gray value extreme point are moved to the left; When the difference is not within the preset tolerance threshold range and the second CD value is less than the first CD value, in the gray value distribution cross-sectional diagram, the pixel point coordinates based on the first gray value extreme point are moved to the left and the pixel point coordinates based on the second gray value extreme point are moved to the right; When the difference between the CD values ​​corresponding to the first pixel point and the second pixel point obtained after the movement and the first CD value is within the tolerance threshold range, the first pixel point is determined to be the third grayscale extreme point and the second pixel point is determined to be the fourth grayscale extreme point.

7. The method for graphically outputting measurement results according to claim 6, characterized in that: The updating of the first measurement parameter according to the third grayscale extreme value point and the fourth grayscale extreme value point comprises: Obtaining a grayscale difference between the third grayscale extreme value point and the first grayscale extreme value point or obtaining a grayscale difference between the fourth grayscale extreme value point and the second grayscale extreme value point; Calculate the percentage of the grayscale difference to the grayscale value of the first grayscale extreme value point or to the grayscale value of the second grayscale extreme value point; The percentage is determined as the updated first measurement parameter.

8. The method for graphically outputting measurement results according to claim 7, characterized in that: The step of extracting a third measurement result of the scanned image according to the updated first measurement parameter and generating a digitized image corresponding to the third measurement result includes: Extracting a third grayscale extreme value point and a fourth grayscale extreme value point in each grayscale value distribution cross-sectional diagram in the scanned image according to the updated first measurement parameter; Connecting all the third grayscale extreme value points to form a first measurement edge; Connecting all of the fourth grayscale extreme value points to form a second measurement edge; A corresponding digitized image is generated based on the first measured edge, the second measured edge, and the scanned image.

9. A graphical output system for measurement results, characterized in that: The system includes a first measurement module, an extreme point extraction module, a second measurement module, an extreme point update module and a measurement graphical module; The first measurement module is used to collect a scanned image corresponding to the sample to be measured under a microscope, and obtain a first measurement result of the scanned image based on a preset first measurement parameter; The extreme value point extraction module is used to obtain a gray value distribution cross-sectional diagram of the scanned image, so as to extract a first gray value extreme value point and a second gray value extreme value point corresponding to the scanned image according to the gray value distribution cross-sectional diagram and the first measurement parameter; The second measurement module is used to calculate a second measurement result corresponding to the scanned image according to the first grayscale extreme value point and the second grayscale extreme value point; The extreme value point updating module is used to obtain the difference between the first measurement result and the second measurement result, so as to update the first grayscale extreme value point and the second grayscale extreme value point according to the difference, and obtain the third grayscale extreme value point and the fourth grayscale extreme value point; The measurement graphical module is used to update the first measurement parameter according to the third grayscale extreme point and the fourth grayscale extreme point, so as to extract a third measurement result of the scanned image according to the updated first measurement parameter and generate a digitized image corresponding to the third measurement result.

10. A graphical output system for measurement results according to claim 9, characterized in that: The first measurement module includes a scanning unit and a measurement unit; The scanning unit is used to obtain a CDSEM image corresponding to the sample to be tested; The measuring unit is used to measure the CDSEM image based on preset CDSEM measurement parameters to obtain a first CD value corresponding to the CDSEM image; wherein the CDSEM measurement parameters are set as a gray value interval.

Images