Wafer graph missing value interpolation method, device and equipment based on exposure direction

Abstract

The invention relates to a wafer graph missing value interpolation method, device and equipment based on an exposure direction. The method comprises the following steps: acquiring an initial measurement wafer graph after a silicon wafer is scanned and developed along a first exposure direction; obtaining at least one crystal grain missing position on the preliminary measurement wafer graph; setting an exposure influence factor of the preliminary measurement wafer graph based on the first exposure direction; calculating a missing value of each crystal grain missing position based on the exposure influence factor and a first distance between each crystal grain missing position and a plurality of preset nearest crystal grain positions; and interpolating the missing value of each crystal grain missing position into the preliminary measurement wafer graph to obtain a complete wafer graph of the silicon wafer. By adopting the method, wafer graph missing value interpolation closer to real crystal grain distribution characteristics can be realized, and the effectiveness of performing characteristic analysis and data calculation by utilizing the complete wafer graph is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a method, device and equipment for interpolating missing values ​​of a wafer image based on exposure direction. Background Art

[0002] In the manufacturing process of semiconductor chips, the measurement data of the dies in the silicon wafer is an important feature of the silicon wafer wafer map.

[0003] During the wafer measurement process, some factors can cause the measurement values ​​of some die locations on the wafer map to be lost. For example, technical problems or anomalies in the measurement process may cause some die locations to not generate any data. In addition, in some cases, some die locations may not be included in the measurement plan, resulting in missing values. In order to facilitate the use of wafer maps of silicon wafers for feature analysis and data learning, it is necessary to increase the amount of valid die measurement data in the wafer map.

[0004] In the prior art, although interpolation algorithms for missing grain positions are widely used, these methods fail to fully consider the unique characteristics of the lithography process when processing wafer image data obtained by critical dimension scanning electron microscopy (CD-SEM) after development in the lithography process. Therefore, the interpolation results obtained often cannot accurately reflect the actual situation, resulting in deviations from the true value. This not only affects the accuracy of the interpolated data, but may also cause the subsequent feature analysis results based on these data to deviate from reality and fail to provide reliable analysis conclusions. Summary of the invention

[0005] Based on this, it is necessary to provide a method, device, computer equipment, computer-readable storage medium and computer program product for wafer image missing value interpolation based on exposure direction, which can improve the calculation accuracy of missing values ​​of missing positions of grains in wafer images, in order to solve the above technical problems.

[0006] In a first aspect, the present application provides a method for interpolating missing values ​​of a wafer image based on an exposure direction, the method comprising:

[0007] Acquire a preliminary measurement wafer image of the silicon wafer after scanning and developing along a first exposure direction;

[0008] Obtaining at least one missing die position on the preliminary measured wafer map;

[0009] Based on the first exposure direction, setting an exposure influencing factor of the preliminary measured wafer image;

[0010] Calculating a missing value of each of the missing grain positions based on the exposure influencing factor and a first distance between each of the missing grain positions and a plurality of preset nearest neighboring grain positions;

[0011] The missing values ​​of each of the missing die positions are interpolated into the preliminary measured wafer map to obtain a complete wafer map of the silicon wafer.

[0012] In one embodiment, the first exposure direction includes an x-axis direction or a y-axis direction, and the exposure influencing factor of the preliminary measured wafer image is set based on the first exposure direction, including:

[0013] If the first exposure direction is the x-axis direction, setting the exposure influence factor of the preliminary measured wafer image to be infinitely close to 0;

[0014] If the first exposure direction is the y-axis direction, the exposure influence factor of the preliminary measured wafer image is set to be infinitely close to A, where A is an arbitrary constant greater than zero.

[0015] In one embodiment, the calculating the missing value of each of the missing grain positions based on the exposure influencing factor and the first distance between each of the missing grain positions and a plurality of nearest adjacent grain positions comprises:

[0016] According to the exposure influencing factor, correcting the first distance between each of the missing grain positions and a plurality of preset nearest grain positions to obtain a second distance between each of the missing grain positions and each of the preset nearest grain positions;

[0017] Calculating, according to the second distance, a similarity weight between each of the missing grain positions and each of the preset nearest grain positions;

[0018] Obtaining a preset grain value of each of the nearest grain positions;

[0019] The missing value of the grain missing position is calculated according to the similarity weight between each of the grain missing positions and each of the preset nearest grain positions and the grain value of each of the nearest grain positions.

[0020] In one embodiment, the Euclidean distance between each of the missing grain positions and a plurality of preset nearest grain positions is corrected according to the exposure influencing factor to obtain a second distance between each of the missing grain positions and each of the preset nearest grain positions, comprising:

[0021] The first distance between each of the missing grain positions and a plurality of preset nearest grain positions is corrected according to the exposure influencing factor using the following formula:

[0022]

[0023] Among them, d(X i , X j) represents the second distance between each of the missing grain positions and each of the preset nearest grain positions; A is an arbitrary constant greater than zero; α∈(0,A) represents the exposure influence factor; X i Indicates the location of grain loss, (x i ,y i ) is the coordinate of the missing position of the grain; X j represents the position of the nearest grain, (x j ,y j ) are the coordinates of the position of the nearest grain.

[0024] In one embodiment, the calculating the missing value of the grain missing position according to the similarity weight between each grain missing position and each preset nearest grain position and the grain value of each nearest grain position comprises:

[0025] The missing value of the grain missing position is calculated using the following formula according to the similarity weight between each of the grain missing positions and each of the preset nearest grain positions and the grain value of each of the nearest grain positions:

[0026]

[0027] in, represents the missing value of the missing position of the grain; x ij Indicates the grain value of the nearest grain position with abscissa i and ordinate j; ω j represents the similarity weight between each of the missing grain positions and each of the preset nearest neighboring grain positions; k represents the number of the preset nearest neighboring grain positions.

[0028] In one embodiment, obtaining a preliminary measurement wafer image of the silicon wafer after scanning and developing along the first exposure direction includes:

[0029] Acquire raw data of a silicon wafer after scanning and developing along a first exposure direction; the raw data includes a critical dimension or line width roughness corresponding to a grain position scanned and developed on the silicon wafer;

[0030] The preliminary measurement wafer map is generated according to the critical dimension or line width roughness corresponding to the grain position scanned and developed on the silicon wafer.

[0031] In a second aspect, the present application further provides a device for interpolating missing values ​​of a wafer image based on an exposure direction, the device comprising:

[0032] An image acquisition module, used for acquiring a preliminary measurement wafer image of the silicon wafer after scanning and developing along a first exposure direction;

[0033] A missing location module, used to obtain at least one missing die position on the preliminary measured wafer map;

[0034] A factor adjustment module, used for setting the exposure influence factor of the preliminary measured wafer image based on the first exposure direction;

[0035] A missing value calculation module, used for calculating the missing value of each of the missing grain positions based on the exposure influencing factor and a first distance between each of the missing grain positions and a plurality of preset nearest neighboring grain positions;

[0036] The image output module is used to interpolate the missing values ​​of each of the missing grain positions into the preliminary measured wafer image to obtain a complete wafer image of the silicon wafer.

[0037] In a third aspect, the present application further provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the contents described in the first aspect when executing the computer program.

[0038] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the contents described in the first aspect above.

[0039] In a fifth aspect, the present application also provides a computer program product, including a computer program, which implements the content described in the first aspect above when executed by a processor.

[0040] The above-mentioned method, device and equipment for interpolating missing values ​​of wafer images based on exposure direction obtain a preliminary measured wafer image after scanning and developing the silicon wafer along a first exposure direction; obtain at least one grain missing position on the preliminary measured wafer image; based on the first exposure direction, set the exposure influence factor of the preliminary measured wafer image; based on the exposure influence factor and the first distance between each of the grain missing positions and a plurality of preset nearest grain positions, calculate the missing value of each of the grain missing positions; interpolate the missing value of each of the grain missing positions into the preliminary measured wafer image to obtain a complete wafer image of the silicon wafer, thereby achieving wafer image missing value interpolation that is closer to the actual grain distribution characteristics, and improving the effectiveness of feature analysis and data calculation using the complete wafer image. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 A diagram of an application environment of a wafer image missing value interpolation method based on exposure direction in one embodiment;

[0043] Figure 2 It is a schematic flow chart of a method for interpolating missing values ​​of a wafer image based on an exposure direction in one embodiment;

[0044] Figure 3 A schematic flow chart of a step of calculating missing values ​​of missing positions of each grain in an embodiment;

[0045] Figure 4 A schematic diagram of a process for obtaining a preliminary measurement wafer map in one embodiment;

[0046] Figure 5 A schematic diagram of a preliminary measurement of a wafer image in one embodiment;

[0047] Figure 6 is a schematic diagram of a complete wafer map in a preferred embodiment;

[0048] Figure 7 is a structural block diagram of a wafer image missing value interpolation device based on exposure direction in one embodiment;

[0049] Figure 8 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0051] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, "A and / or B" can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0052] The wafer image missing value interpolation method based on exposure direction provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown, the terminal 102 communicates with the server 104 through a network. The data storage system can store data that the server 104 needs to process. The data storage system can be integrated on the server 104, or placed on the cloud or other network servers.

[0053] On the server 104, a preliminary measurement wafer image of the silicon wafer after scanning and development along a first exposure direction is obtained; at least one grain missing position on the preliminary measurement wafer image is obtained; based on the first exposure direction, an exposure influence factor of the preliminary measurement wafer image is set; based on the exposure influence factor and a first distance between each of the grain missing positions and a plurality of preset nearest grain positions, a missing value of each of the grain missing positions is calculated; and the missing value of each of the grain missing positions is interpolated into the preliminary measurement wafer image to obtain a complete wafer image of the silicon wafer.

[0054] The terminal 102 may be, but is not limited to, a photolithography machine, a critical dimension scanning electron microscope, various personal computers connected to a critical dimension scanning electron microscope, a laptop computer, a smart phone, a tablet computer, an Internet of Things device, etc. The server 104 may be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services.

[0055] In an exemplary embodiment, Figure 2 As shown in FIG. 1 , a wafer image missing value interpolation method based on exposure direction is provided, and the method is applied to Figure 1 The server side in the example is used to illustrate, including the following steps 201 to 205. Among them:

[0056] Step 201 , obtaining a preliminary measurement wafer image of a silicon wafer after scanning and development along a first exposure direction.

[0057] Specifically, when extracting the wafer map of the silicon wafer, the photolithography machine usually sets the scanning direction when the wafer is exposed. After the photolithography machine scans and develops the silicon wafer along the first exposure direction, the original data of the silicon wafer is obtained. The server generates a preliminary measurement wafer map of the silicon wafer after scanning and developing along the first exposure direction based on the original data.

[0058] Step 202, obtaining at least one missing die position on the preliminary measurement wafer map.

[0059] Specifically, each visible measurement point in the preliminary measurement wafer image has corresponding coordinate information and grain value, while the invisible measurement point is the grain missing position, which has corresponding coordinate information but no measured grain value, i.e., a missing value is generated at the corresponding position.

[0060] Step 203 : setting an exposure influencing factor of the preliminary measured wafer image based on the first exposure direction.

[0061] Step 204 , calculating the missing value of each of the missing grain positions based on the exposure influencing factor and a first distance between each of the missing grain positions and a plurality of preset nearest neighboring grain positions.

[0062] Specifically, when calculating the missing value of a conventional grain missing position, only the influence of the grain values ​​around the missing value on the missing value is considered. This application has been verified through experiments that in the process of calculating the missing value of a grain missing position, by setting an exposure influence factor related to the exposure direction of the lithography machine, the influence proportion of the grain values ​​around the missing value on the missing value is determined, and the grain values ​​of the grain positions with a high correlation with the grain missing position are more accurately selected to calculate the size of the missing value, thereby improving the accuracy of the missing value obtained.

[0063] Step 205 , interpolating the missing values ​​of each of the missing die positions into the preliminary measured wafer map to obtain a complete wafer map of the silicon wafer.

[0064] In the above-mentioned wafer image missing value interpolation method based on exposure direction, a preliminary measured wafer image of a silicon wafer after scanning and development along a first exposure direction is obtained; at least one grain missing position on the preliminary measured wafer image is obtained; based on the first exposure direction, an exposure influence factor of the preliminary measured wafer image is set; based on the exposure influence factor and a first distance between each of the grain missing positions and a plurality of preset nearest neighboring grain positions, the missing value of each of the grain missing positions is calculated; the missing value of each of the grain missing positions is interpolated into the preliminary measured wafer image to obtain a complete wafer image of the silicon wafer, thereby achieving wafer image missing value interpolation that is closer to the actual grain distribution characteristics, and improving the effectiveness of feature analysis and data calculation using a complete wafer image.

[0065] In an exemplary embodiment, the first exposure direction includes an x-axis direction or a y-axis direction, and step 203 sets the exposure influencing factor of the preliminary measured wafer image based on the first exposure direction, specifically including the following contents:

[0066] If the first exposure direction is the x-axis direction, the exposure influence factor of the preliminary measured wafer image is set to be infinitely close to 0; if the first exposure direction is the y-axis direction, the exposure influence factor of the preliminary measured wafer image is set to be infinitely close to A, where A is an arbitrary constant greater than zero.

[0067] In detail, in the process of calculating the first distance between the grain missing position and the preset multiple nearest neighboring grain positions, if the exposure influence factor α is used as the calculation weight of the vertical coordinate parameter of the grain position in the wafer image, the calculation weight of the horizontal coordinate parameter is set to (A-α). If the first exposure direction is the x-axis direction, it means that the horizontal coordinate parameter of the nearest neighboring grain position has the greatest influence on the grain missing position, and the exposure influence factor of the preliminary measured wafer image is set to be infinitely close to 0, and the horizontal coordinate parameter is increased in the calculation participation of the first distance; if the first exposure direction is the y-axis direction, it means that the vertical coordinate parameter of the nearest neighboring grain position has the greatest influence on the grain missing position, and the exposure influence factor of the preliminary measured wafer image is set to be infinitely close to A, and the vertical coordinate parameter is increased in the calculation participation of the first distance.

[0068] Optionally, the exposure influence factor α can also be used as the calculation weight of the horizontal coordinate parameter of the grain position in the wafer image, and the calculation weight of the vertical coordinate parameter is set to (A-α). At this time, the setting process of the exposure influence factor is opposite to the setting process in the above embodiment.

[0069] In this embodiment, the size of the exposure influencing factor is set according to the first exposure direction, so as to adjust the value of the first distance between the missing grain position and the nearest grain position, and finally improve the calculation accuracy of the missing value of the missing grain position.

[0070] In one embodiment, if Figure 3 The step 204 calculates the missing value of each of the missing grain positions based on the exposure influencing factor and the first distance between each of the missing grain positions and a plurality of the most adjacent grain positions, and specifically includes the following steps 301 to 304. Among them:

[0071] Step 301 : Correcting a first distance between each of the missing grain positions and a plurality of preset nearest grain positions according to the exposure influencing factor to obtain a second distance between each of the missing grain positions and each of the preset nearest grain positions.

[0072] Step 302: Calculate the similarity weight between each of the missing grain positions and each of the preset nearest grain positions according to the second distance.

[0073] Step 303, obtaining a preset grain value of each of the nearest grain positions.

[0074] Step 304 , calculating the missing value of the missing grain position according to the similarity weight between each missing grain position and each preset nearest grain position and the grain value of each nearest grain position.

[0075] Specifically, the first distance between each of the missing grain positions and the preset plurality of nearest grain positions is corrected according to the exposure influencing factor using the following formula:

[0076]

[0077] Among them, d(X i , X j ) represents the second distance between each of the missing grain positions and each of the preset nearest grain positions; A is an arbitrary constant greater than zero; α∈(0,A) represents the exposure influence factor; X i Indicates the location of grain loss, (x i ,y i ) is the coordinate of the missing position of the grain; X j represents the position of the nearest grain, (x j ,y j ) are the coordinates of the position of the nearest grain.

[0078] Further, the missing value of the missing grain position is calculated according to the similarity weight between each missing grain position and each preset nearest grain position and the grain value of each nearest grain position using the following formula:

[0079]

[0080] in, represents the missing value of the missing position of the grain; x ij Indicates the grain value of the nearest grain position with abscissa i and ordinate j; ω j represents the similarity weight between each of the missing grain positions and each of the preset nearest neighboring grain positions; k represents the number of the preset nearest neighboring grain positions.

[0081] Wherein, the similarity weight ω between each of the missing grain positions and each of the preset nearest grain positions is j is the reciprocal of the second distance:

[0082]

[0083] Among them, the role of ∈ is to make the denominator non-zero.

[0084] In this embodiment, the first distance between each of the grain missing positions and the preset multiple nearest grain positions is corrected by the exposure influence factor to obtain the second distance between each grain missing position and each preset nearest grain position, thereby improving the accuracy of the similarity weight of the missing value of each nearest grain position to the grain missing position, and ultimately improving the calculation accuracy of the missing value at the grain missing position, thereby achieving high-precision wafer image missing value interpolation.

[0085] In one embodiment, Figure 4 As shown, step 201 obtains a preliminary measurement wafer image after the silicon wafer is scanned and developed along the first exposure direction, specifically including the following steps 401 to 402. Among them:

[0086] Step 401 , obtaining raw data of a silicon wafer after scanning and developing along a first exposure direction; the raw data includes a critical dimension or line width roughness corresponding to a grain position scanned and developed on the silicon wafer.

[0087] Among them, the critical dimension can be set as dense critical dimension or sparse critical dimension according to the user's needs for the wafer map. The same is true for line width roughness.

[0088] Step 402 , generating the preliminary measurement wafer map according to the critical dimension or line width roughness corresponding to the grain positions scanned and developed on the silicon wafer.

[0089] Specifically, the preliminary measurement wafer map generated according to the dense critical dimension is a dense pattern, and the preliminary measurement wafer map generated according to the sparse critical dimension is a sparse pattern. The preliminary measurement wafer map generated according to the dense line width roughness is a dense pattern, and the preliminary measurement wafer map generated according to the sparse line width roughness is a sparse pattern. For example, Figure 5 The preliminary measurement wafer map shown is a sparse pattern generated based on the sparse critical dimensions, where the depth of color represents the numerical size of the critical dimensions.

[0090] In this embodiment, a preliminary measurement wafer map of the silicon wafer is generated by acquiring the critical dimension or line width roughness corresponding to the grain positions scanned and developed on the silicon wafer.

[0091] In a preferred embodiment, a method for interpolating missing values ​​of a wafer image based on an exposure direction is provided, wherein the exposure direction of the lithography machine is the y-axis direction, and specifically includes the following contents:

[0092] Step 1: Obtain the critical dimension corresponding to each grain position of the silicon wafer after scanning and developing along the first exposure direction, and generate a preliminary measurement wafer map of the silicon wafer along the y-axis exposure direction.

[0093] Step 2: Obtain each missing die position on the preliminary measurement wafer map.

[0094] Step 3: Based on the Y-axis exposure direction, set the exposure influence factor α of the preliminary measured wafer image to be infinitely close to A.

[0095] Step 4: According to the exposure influence factor α, the first distance between each of the missing grain positions and the preset k nearest neighboring grain positions is corrected to obtain the second distance d (X i , X j ):

[0096]

[0097] Among them, d(X i , X j ) represents the second distance between each of the missing grain positions and each of the preset nearest grain positions; A is an arbitrary constant greater than zero; α∈(0,A) represents the exposure influence factor; X i Indicates the location of grain loss, (x i ,y i ) is the coordinate of the missing position of the grain; X j represents the position of the nearest grain, (x j ,y j ) are the coordinates of the position of the nearest grain.

[0098] Step 5: Calculate the similarity weight ω between each of the missing grain positions and each of the preset nearest grain positions according to the second distance. j :

[0099] Step 6: Get the grain value x of each nearest grain position ij , according to the similarity weight ω between each missing grain position and each preset nearest grain position j , the grain value of each nearest grain position, and the missing value of the missing grain position are calculated:

[0100]

[0101] in, The missing value represents the position where the grain is missing; x ij Indicates the grain value of the nearest grain position with abscissa i and ordinate j; ω j represents the similarity weight between each grain missing position and each preset nearest grain position; k represents the number of nearest grain positions.

[0102] Step 7: interpolate the missing values ​​of the missing positions of each die into the preliminary measured wafer map to obtain a complete wafer map of the silicon wafer.

[0103] like Figure 6 As shown, the left side is a wafer image obtained by a conventional interpolation method, and the right side is a complete wafer image obtained by the wafer image missing value interpolation method based on the exposure direction of this application, where the color represents the numerical size of the key dimension.

[0104] In order to demonstrate the superior performance of the wafer image missing value interpolation method based on the exposure direction of the present application compared with the conventional interpolation method, the critical dimension uniformity or linear roughness uniformity of the wafer image is used as the evaluation characteristic parameter. For example, the calculation method of the critical dimension uniformity is:

[0105]

[0106] Among them, σ represents, Represents the average value of the critical dimension at all grain locations.

[0107] The critical dimension uniformity of the interpolated wafer image and the critical dimension of the original data are calculated for the two interpolation methods, and the critical dimension uniformity CDU of the wafer image is shown in Table 1 below:

[0108] Table 1

[0109]

[0110] The purpose of interpolating the wafer image is to expand the data while minimizing the impact of the interpolation on the critical dimension uniformity CDU of the original data. From this table, it can be seen that the wafer image missing value interpolation method based on the exposure direction of this application is closer to the original data in terms of critical dimension uniformity CDU than the conventional interpolation method, regardless of whether the obtained complete wafer image is a dense image or a sparse image.

[0111] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0112] Based on the same inventive concept, the embodiment of the present application also provides a device for interpolating missing values ​​of a wafer image based on exposure direction for implementing the method for interpolating missing values ​​of a wafer image based on exposure direction mentioned above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more embodiments of the device for interpolating missing values ​​of a wafer image based on exposure direction provided below can refer to the limitations of the method for interpolating missing values ​​of a wafer image based on exposure direction above, and will not be repeated here.

[0113] In an exemplary embodiment, Figure 7 As shown, a wafer image missing value interpolation device based on exposure direction is provided, comprising: an M module, an N module and an L module, wherein:

[0114] The image acquisition module 701 is used to acquire a preliminary measurement wafer image of the silicon wafer after scanning and development along the first exposure direction.

[0115] The missing location module 702 is used to obtain at least one missing die position on the preliminary measured wafer map.

[0116] The factor adjustment module 703 is used to set the exposure influencing factor of the preliminary measured wafer image based on the first exposure direction.

[0117] The missing value calculation module 704 is used to calculate the missing value of each of the missing grain positions based on the exposure influencing factor and the first distance between each of the missing grain positions and a plurality of preset nearest neighboring grain positions.

[0118] The image output module 705 is used to interpolate the missing values ​​of each of the missing die positions into the preliminary measured wafer image to obtain a complete wafer image of the silicon wafer.

[0119] In one embodiment, the first exposure direction includes the x-axis direction or the y-axis direction, and the factor adjustment module 703 is further used to: if the first exposure direction is the x-axis direction, then set the exposure influence factor of the preliminary measured wafer image to be infinitely close to 0; if the first exposure direction is the y-axis direction, then set the exposure influence factor of the preliminary measured wafer image to be infinitely close to A, where A is an arbitrary constant greater than zero.

[0120] In one embodiment, the missing value calculation module 704 is also used to: correct the first distance between each of the grain missing positions and the preset multiple nearest grain positions according to the exposure influencing factor to obtain the second distance between each of the grain missing positions and each of the preset nearest grain positions; calculate the similarity weight between each of the grain missing positions and each of the preset nearest grain positions according to the second distance; obtain the grain value of each of the preset nearest grain positions; calculate the missing value of the grain missing position according to the similarity weight between each of the grain missing positions and each of the preset nearest grain positions and the grain value of each nearest grain position.

[0121] In one embodiment, the missing value calculation module 704 is further used to correct the first distance between each of the missing grain positions and a plurality of preset nearest grain positions according to the exposure influencing factor using the following formula:

[0122]

[0123] Among them, d(X i , X j ) represents the second distance between each of the missing grain positions and each of the preset nearest grain positions; A is an arbitrary constant greater than zero; α∈(0,A) represents the exposure influence factor; X i Indicates the location of grain loss, (x i ,y i ) is the coordinate of the missing position of the grain; X j represents the position of the nearest grain, (x j ,y j ) are the coordinates of the position of the nearest grain.

[0124] In one embodiment, the missing value calculation module 704 is further used to calculate the missing value of the grain missing position according to the similarity weight between each grain missing position and each preset nearest grain position and the grain value of each nearest grain position using the following formula:

[0125]

[0126] in, represents the missing value of the missing position of the grain; x ij Indicates the grain value of the nearest grain position with abscissa i and ordinate j; ω j represents the similarity weight between each of the missing grain positions and each of the preset nearest neighboring grain positions; k represents the number of the preset nearest neighboring grain positions.

[0127] In one embodiment, the image acquisition module 701 is also used to: acquire original data of the silicon wafer after scanning and development along the first exposure direction; the original data includes the critical dimensions or line width roughness corresponding to the grain positions scanned and developed on the silicon wafer; and generate the preliminary measured wafer map based on the critical dimensions or line width roughness corresponding to the grain positions scanned and developed on the silicon wafer.

[0128] Each module in the above-mentioned wafer image missing value interpolation device based on exposure direction can be implemented in whole or in part by software, hardware and their combination. Each of the above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

[0129] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in FIG. Figure 8As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store wafer image data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for interpolating missing values ​​of a wafer image based on an exposure direction is implemented.

[0130] Those skilled in the art will understand that Figure 8 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0131] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0132] Acquire a preliminary measurement wafer image of the silicon wafer after scanning and developing along a first exposure direction;

[0133] Obtaining at least one missing die position on the preliminary measured wafer map;

[0134] Based on the first exposure direction, setting an exposure influencing factor of the preliminary measured wafer image;

[0135] Calculating a missing value of each of the missing grain positions based on the exposure influencing factor and a first distance between each of the missing grain positions and a plurality of preset nearest neighboring grain positions;

[0136] The missing values ​​of each of the missing die positions are interpolated into the preliminary measured wafer map to obtain a complete wafer map of the silicon wafer.

[0137] In one embodiment, the first exposure direction includes the x-axis direction or the y-axis direction, and the processor further implements the following steps when executing the computer program: if the first exposure direction is the x-axis direction, the exposure influence factor of the preliminary measured wafer image is set to be infinitely close to 0; if the first exposure direction is the y-axis direction, the exposure influence factor of the preliminary measured wafer image is set to be infinitely close to A, where A is an arbitrary constant greater than zero.

[0138] In one embodiment, when the processor executes the computer program, the following steps are also implemented: according to the exposure influencing factor, the first distance between each of the grain missing positions and the preset multiple nearest grain positions is corrected to obtain the second distance between each of the grain missing positions and each of the preset nearest grain positions; according to the second distance, the similarity weight between each of the grain missing positions and each of the preset nearest grain positions is calculated; the grain value of each of the preset nearest grain positions is obtained; according to the similarity weight between each of the grain missing positions and each of the preset nearest grain positions and the grain value of each nearest grain position, the missing value of the grain missing position is calculated.

[0139] In one embodiment, when the processor executes the computer program, the following steps are further implemented: correcting the first distance between each of the missing grain positions and a plurality of preset nearest grain positions according to the exposure influencing factor using the following formula:

[0140]

[0141] Among them, d(X i , X j ) represents the second distance between each of the missing grain positions and each of the preset nearest grain positions; A is an arbitrary constant greater than zero; α∈(0,A) represents the exposure influence factor; X i Indicates the location of grain loss, (x i ,y i ) is the coordinate of the missing position of the grain; X j represents the position of the nearest grain, (x j ,y j ) are the coordinates of the position of the nearest grain.

[0142] In one embodiment, when the processor executes the computer program, the following steps are further implemented: using the following formula, according to the similarity weight between each of the missing grain positions and each of the preset nearest grain positions, and the grain value of each of the nearest grain positions, the missing value of the missing grain position is calculated:

[0143]

[0144] in, represents the missing value of the missing position of the grain; x ij Indicates the grain value of the nearest grain position with abscissa i and ordinate j; ω j represents the similarity weight between each of the missing grain positions and each of the preset nearest neighboring grain positions; k represents the number of the preset nearest neighboring grain positions.

[0145] In one embodiment, when the processor executes the computer program, the following steps are also implemented: obtaining raw data of the silicon wafer after scanning and development along the first exposure direction; the raw data includes the critical dimensions or line width roughness corresponding to the grain positions scanned and developed on the silicon wafer; and generating the preliminary measured wafer map according to the critical dimensions or line width roughness corresponding to the grain positions scanned and developed on the silicon wafer.

[0146] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps corresponding to the wafer image missing value interpolation method based on the exposure direction as described in the above embodiments are implemented.

[0147] In one embodiment, a computer program product is provided, including a computer program, which, when executed by a processor, implements the steps corresponding to the wafer image missing value interpolation method based on the exposure direction as described in the above embodiments.

[0148] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0149] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0150] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for interpolating missing values ​​of a wafer image based on exposure direction, characterized in that: The method comprises: Acquire a preliminary measurement wafer image of the silicon wafer after scanning and developing along a first exposure direction; Obtaining at least one missing die position on the preliminary measured wafer map; Based on the first exposure direction, setting an exposure influencing factor of the preliminary measured wafer image; Calculating a missing value of each of the missing grain positions based on the exposure influencing factor and a first distance between each of the missing grain positions and a plurality of preset nearest neighboring grain positions; The missing values ​​of each of the missing die positions are interpolated into the preliminary measured wafer map to obtain a complete wafer map of the silicon wafer.

2. The method for interpolating missing values ​​of a wafer image based on exposure direction according to claim 1, characterized in that: The first exposure direction includes an x-axis direction or a y-axis direction, and the exposure influencing factor of the preliminary measured wafer image is set based on the first exposure direction and includes: If the first exposure direction is the x-axis direction, setting the exposure influence factor of the preliminary measured wafer image to be infinitely close to 0; If the first exposure direction is the y-axis direction, the exposure influence factor of the preliminary measured wafer image is set to be infinitely close to A, where A is an arbitrary constant greater than zero.

3. The method for interpolating missing values ​​of a wafer image based on exposure direction according to claim 2, characterized in that: The step of calculating the missing value of each of the missing grain positions based on the exposure influencing factor and the first distance between each of the missing grain positions and a plurality of the most adjacent grain positions comprises: According to the exposure influencing factor, correcting the first distance between each of the missing grain positions and a plurality of preset nearest grain positions to obtain a second distance between each of the missing grain positions and each of the preset nearest grain positions; Calculating, according to the second distance, a similarity weight between each of the missing grain positions and each of the preset nearest grain positions; Obtaining a preset grain value of each of the nearest grain positions; The missing value of the grain missing position is calculated according to the similarity weight between each of the grain missing positions and each of the preset nearest grain positions and the grain value of each of the nearest grain positions.

4. The method for interpolating missing values ​​of a wafer image based on exposure direction according to claim 3, characterized in that: The step of correcting the Euclidean distance between each of the missing grain positions and a plurality of preset nearest grain positions according to the exposure influencing factor to obtain a second distance between each of the missing grain positions and each of the preset nearest grain positions includes: The first distance between each of the missing grain positions and a plurality of preset nearest grain positions is corrected according to the exposure influencing factor using the following formula: Among them, d(X i , X j ) represents the second distance between each of the missing grain positions and each of the preset nearest grain positions; A is an arbitrary constant greater than zero; α∈(0,A) represents the exposure influence factor; X i Indicates the location of grain loss, (x i ,y i ) is the coordinate of the missing position of the grain; X j represents the position of the nearest grain, (x j ,y j ) are the coordinates of the position of the nearest grain.

5. The method for interpolating missing values ​​of a wafer image based on exposure direction according to claim 4, characterized in that: The step of calculating the missing value of the missing grain position according to the similarity weight between each missing grain position and each preset nearest grain position and the grain value of each nearest grain position comprises: The missing value of the grain missing position is calculated using the following formula according to the similarity weight between each of the grain missing positions and each of the preset nearest grain positions and the grain value of each of the nearest grain positions: in, represents the missing value of the missing position of the grain; x ij Indicates the grain value of the nearest grain position with abscissa i and ordinate j; ω j represents the similarity weight between each of the missing grain positions and each of the preset nearest neighboring grain positions; k represents the number of the preset nearest neighboring grain positions.

6. The method for interpolating missing values ​​of a wafer image based on exposure direction according to claim 1, characterized in that: The method of obtaining a preliminary measurement wafer image after scanning and developing the silicon wafer along the first exposure direction comprises: Acquire raw data of a silicon wafer after scanning and developing along a first exposure direction; the raw data includes a critical dimension or line width roughness corresponding to a grain position scanned and developed on the silicon wafer; The preliminary measurement wafer map is generated according to the critical dimension or line width roughness corresponding to the grain position scanned and developed on the silicon wafer.

7. A wafer image missing value interpolation device based on exposure direction, characterized in that: The device comprises: An image acquisition module, used for acquiring a preliminary measurement wafer image of the silicon wafer after scanning and developing along a first exposure direction; A missing location module, used to obtain at least one missing die position on the preliminary measured wafer map; A factor adjustment module, used for setting the exposure influence factor of the preliminary measured wafer image based on the first exposure direction; A missing value calculation module, used for calculating the missing value of each of the missing grain positions based on the exposure influencing factor and a first distance between each of the missing grain positions and a plurality of preset nearest neighboring grain positions; The image output module is used to interpolate the missing values ​​of each of the missing grain positions into the preliminary measured wafer image to obtain a complete wafer image of the silicon wafer.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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