Method and device for calibrating photoetching machine and photoetching machine

Abstract

The invention discloses a method and device for calibrating a photoetching machine and the photoetching machine, and the method comprises the steps: calculating theoretical position data corresponding to a plurality of measurement patterns on a mask on a wafer based on an exposure grid of a to-be-calibrated photoetching machine; exposing the plurality of measurement patterns to the wafer by using a to-be-calibrated photoetching machine to obtain a plurality of exposure patterns on the wafer; measuring the actual position of each exposure pattern on the wafer to obtain measurement position data of each exposure pattern; determining exposure grid deviation based on the deviation between the first theoretical distance of each measurement pattern and the first measurement distance of the corresponding exposure pattern and the deviation between the second theoretical distance of each measurement pattern and the second measurement distance of the corresponding exposure pattern; and performing compensation calibration on the exposure grid of the to-be-calibrated photoetching machine based on the exposure grid deviation, so that the to-be-calibrated photoetching machine can be quickly calibrated at a relatively reasonable position in the absence of a standard photoetching machine and a standard calibration sheet.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, specifically to a calibration method, apparatus, and lithography machine for a lithography machine. Background Technology

[0002] For newly built semiconductor manufacturing plants, the lack of high-precision, high-stability standard lithography machines and the absence of standard calibration discs specifically used for calibrating and verifying lithography machines leads to exposure deviations in the lithography machines (such as the first lithography machine to arrive at the plant). Summary of the Invention

[0003] To address the problems of the prior art, this application provides a calibration method, apparatus, and lithography machine for a photolithography machine. The technical solution is as follows: On the one hand, a calibration method for a lithography machine is provided, including: Based on the exposure grid of the lithography machine to be calibrated, the theoretical position data corresponding to multiple measurement patterns on the mask on the wafer are calculated respectively; the theoretical position data corresponding to each measurement pattern includes a first theoretical distance and a second theoretical distance, the first theoretical distance represents the distance from the wafer edge in the horizontal direction, and the second theoretical distance represents the distance from the wafer edge in the vertical direction; The multiple measurement patterns on the photomask are exposed onto the wafer using the lithography machine to be calibrated, resulting in multiple exposure patterns on the wafer; The actual position of each of the exposed patterns on the wafer is measured to obtain measurement position data for each of the exposed patterns; the measurement position data includes a first measurement distance and a second measurement distance, wherein the first measurement distance represents the distance from the edge of the wafer in the horizontal direction, and the second measurement distance represents the distance from the edge of the wafer in the vertical direction; The exposure grid deviation is determined based on the deviation between the first theoretical distance of each of the measured patterns and the first measured distance of the corresponding exposure pattern, and the deviation between the second theoretical distance of each of the measured patterns and the second measured distance of the corresponding exposure pattern. Based on the exposure grid deviation, the exposure grid of the lithography machine to be calibrated is compensated and calibrated.

[0004] In some embodiments, measuring the actual position of each of the exposed patterns on the wafer to obtain measurement position data for each of the exposed patterns includes: For each of the exposure patterns, the actual coordinates of multiple key points on the wafer are measured; the multiple key points include the intersection point where the exposure grid falls into the exposure pattern, the horizontal extension point of the cross, and the vertical extension point of the cross, wherein the horizontal extension point of the cross is the intersection point extending from the intersection point along the horizontal direction to the edge of the wafer, and the vertical extension point of the cross is the intersection point extending from the intersection point along the vertical direction to the edge of the wafer. Based on the actual coordinates of the cross intersection point, the actual coordinates of the horizontal extension point of the cross, and the actual coordinates of the vertical extension point of the cross, the first measurement distance and the second measurement distance corresponding to the exposure pattern are determined.

[0005] In some embodiments, calculating the theoretical position data on the wafer corresponding to multiple measurement patterns on the mask based on the exposure grid of the lithography machine to be calibrated includes: For each of the measurement patterns, based on the exposure grid of the lithography machine to be calibrated, the theoretical coordinates of the multiple key points on the wafer are calculated respectively; Based on the theoretical coordinates of the cross intersection point, the theoretical coordinates of the horizontal extension point of the cross, and the theoretical coordinates of the vertical extension point of the cross, the first theoretical distance and the second theoretical distance corresponding to the measured pattern are determined.

[0006] In some embodiments, the plurality of measurement patterns include a first measurement pattern, a second measurement pattern, a third measurement pattern, and a fourth measurement pattern, wherein the first and second measurement patterns are distributed on one side of the horizontal direction, and the third and fourth measurement patterns are distributed on the other side of the horizontal direction; the first and third measurement patterns are distributed on one side of the vertical direction, and the second and fourth measurement patterns are distributed on the other side of the vertical direction.

[0007] In some embodiments, determining the exposure grid deviation based on the deviation between the first theoretical distance of each of the measured patterns and the first measured distance of the corresponding exposure pattern, and the deviation between the second theoretical distance of each of the measured patterns and the second measured distance of the corresponding exposure pattern, includes: A first horizontal deviation is obtained based on the deviation between the first theoretical distance of the first target measurement pattern and the first measurement distance of the corresponding exposure pattern; a second horizontal deviation is obtained based on the deviation between the first theoretical distance of the second target measurement pattern and the first measurement distance of the corresponding exposure pattern; the first target measurement pattern and the second target measurement pattern are respectively the first measurement pattern and the second measurement pattern, or the first target measurement pattern and the second target measurement pattern are respectively the third measurement pattern and the fourth measurement pattern; The horizontal grid deviation of the exposure grid is determined based on the first horizontal deviation and the second horizontal deviation; A first vertical deviation is obtained based on the deviation between the second theoretical distance of the third target measurement pattern and the second measurement distance of the corresponding exposure pattern; a second vertical deviation is obtained based on the deviation between the second theoretical distance of the fourth target measurement pattern and the second measurement distance of the corresponding exposure pattern; the third target measurement pattern and the fourth target measurement pattern are respectively the first measurement pattern and the third measurement pattern, or the third target measurement pattern and the fourth target measurement pattern are respectively the second measurement pattern and the fourth measurement pattern; The vertical grid deviation of the exposure grid is determined based on the first vertical deviation and the second vertical deviation; The exposure grid deviation includes the horizontal grid deviation and the vertical grid deviation of the exposure grid.

[0008] In some implementations, determining the horizontal grid deviation of the exposure grid based on the first horizontal deviation and the second horizontal deviation includes: The horizontal grid deviation of the exposure grid is obtained by determining half of the sum of the first horizontal deviation and the second horizontal deviation; The determination of the vertical grid deviation of the exposure grid based on the first vertical deviation and the second vertical deviation includes: The vertical grid deviation of the exposure grid is obtained by determining half of the sum of the first vertical deviation and the second vertical deviation.

[0009] On the other hand, a calibration device for a lithography machine is provided, the device comprising: The theoretical position calculation module is configured to calculate the theoretical position data corresponding to multiple measurement patterns on the mask on the wafer based on the exposure grid of the lithography machine to be calibrated. The theoretical position data corresponding to each measurement pattern includes a first theoretical distance and a second theoretical distance. The first theoretical distance represents the distance to the wafer edge in the horizontal direction, and the second theoretical distance represents the distance to the wafer edge in the vertical direction. An exposure module is configured to expose the plurality of measurement patterns on the mask onto the wafer using the lithography machine to be calibrated, thereby obtaining a plurality of exposure patterns on the wafer; A position measurement module is configured to measure the actual position of each of the exposed patterns on the wafer to obtain measurement position data for each of the exposed patterns; the measurement position data includes a first measurement distance and a second measurement distance, the first measurement distance representing the distance from the wafer edge in the horizontal direction, and the second measurement distance representing the distance from the wafer edge in the vertical direction; The grid deviation determination module is configured to determine the exposure grid deviation based on the deviation between the first theoretical distance of each of the measured patterns and the first measured distance of the corresponding exposure pattern, and the deviation between the second theoretical distance of each of the measured patterns and the second measured distance of the corresponding exposure pattern. The calibration module is configured to compensate and calibrate the exposure grid of the lithography machine to be calibrated based on the exposure grid deviation.

[0010] In some embodiments, the position measurement module is specifically configured to measure the actual coordinates of multiple key points on the wafer for each exposure pattern; the multiple key points include the intersection point where the exposure grid falls into the exposure pattern, the horizontal extension point of the cross, and the vertical extension point of the cross, wherein the horizontal extension point is the intersection point extending from the intersection point along the horizontal direction to the edge of the wafer, and the vertical extension point is the intersection point extending from the intersection point along the vertical direction to the edge of the wafer; based on the actual coordinates of the intersection point, the actual coordinates of the horizontal extension point, and the actual coordinates of the vertical extension point, a first measurement distance and a second measurement distance corresponding to the exposure pattern are determined.

[0011] In some embodiments, the theoretical position calculation module is specifically configured to, for each measurement pattern, calculate the theoretical coordinates of the plurality of key points on the wafer based on the exposure grid of the lithography machine to be calibrated; and determine the first theoretical distance and the second theoretical distance corresponding to the measurement pattern based on the theoretical coordinates of the cross intersection point, the theoretical coordinates of the horizontal extension point of the cross, and the theoretical coordinates of the vertical extension point of the cross.

[0012] In some embodiments, the plurality of measurement patterns include a first measurement pattern, a second measurement pattern, a third measurement pattern, and a fourth measurement pattern, wherein the first and second measurement patterns are distributed on one side of the horizontal direction, and the third and fourth measurement patterns are distributed on the other side of the horizontal direction; the first and third measurement patterns are distributed on one side of the vertical direction, and the second and fourth measurement patterns are distributed on the other side of the vertical direction.

[0013] In some implementations, the grid deviation determination module includes: The horizontal deviation determination module is configured to obtain a first horizontal deviation based on the deviation between a first theoretical distance of a first target measurement pattern and a first measurement distance of a corresponding exposure pattern; and to obtain a second horizontal deviation based on the deviation between a first theoretical distance of a second target measurement pattern and a first measurement distance of a corresponding exposure pattern; wherein the first target measurement pattern and the second target measurement pattern are respectively the first measurement pattern and the second measurement pattern, or the first target measurement pattern and the second target measurement pattern are respectively the third measurement pattern and the fourth measurement pattern; A horizontal grid deviation determination module is configured to determine the horizontal grid deviation of the exposure grid based on the first horizontal deviation and the second horizontal deviation; The vertical deviation determination module is configured to obtain a first vertical deviation based on the deviation between a first theoretical distance of a third target measurement pattern and a first measurement distance of a corresponding exposure pattern; and to obtain a second vertical deviation based on the deviation between a first theoretical distance of a fourth target measurement pattern and a first measurement distance of a corresponding exposure pattern; wherein the third target measurement pattern and the fourth target measurement pattern are respectively the first measurement pattern and the third measurement pattern, or the third target measurement pattern and the fourth target measurement pattern are respectively the second measurement pattern and the fourth measurement pattern; A vertical grid deviation determination module is configured to determine the vertical grid deviation of the exposure grid based on the first vertical deviation and the second vertical deviation; The exposure grid deviation includes the horizontal grid deviation and the vertical grid deviation of the exposure grid.

[0014] In some implementations, the horizontal grid deviation determination module is specifically configured to determine half of the sum of the first horizontal deviation and the second horizontal deviation to obtain the horizontal grid deviation of the exposure grid; The vertical deviation determination module is specifically configured to determine half of the sum of the first vertical deviation and the second vertical deviation to obtain the vertical grid deviation of the exposure grid.

[0015] On the other hand, a lithography machine is provided, including a controller and a memory, the memory storing computer instructions that, when executed by the controller, implement the calibration method of the lithography machine described in any of the above aspects.

[0016] This application embodiment calculates the theoretical position data of multiple measurement patterns on the mask on the wafer based on the exposure grid of the lithography machine to be calibrated. The theoretical position data corresponding to each measurement pattern includes a first theoretical distance representing the distance from the wafer edge in the horizontal direction and a second theoretical distance representing the distance from the wafer edge in the vertical direction. The multiple measurement patterns on the mask are exposed onto the wafer using the lithography machine to be calibrated to obtain multiple exposure patterns on the wafer. Then, the actual position of each exposure pattern on the wafer is measured to obtain the measurement position data of each exposure pattern. The measurement position data includes the first measurement data representing the distance from the wafer edge in the horizontal direction and the second measurement distance representing the distance from the wafer edge in the vertical direction. The exposure grid deviation is determined based on the deviation between the first theoretical distance of each measurement pattern and the first measurement distance of the corresponding exposure pattern, and the deviation between the second theoretical distance of each measurement pattern and the second measurement distance of the corresponding exposure pattern. The exposure grid of the lithography machine to be calibrated is compensated and calibrated based on the exposure grid deviation. Thus, even without a standard lithography machine and a standard calibration wafer, the lithography machine to be calibrated (such as the first lithography machine arriving at the factory) can be quickly calibrated to a relatively reasonable position. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic flowchart of a calibration method for a lithography machine provided in an embodiment of this application; Figure 2 This is a schematic diagram of the exposure grid provided in the embodiments of this application; Figure 3 This is a schematic diagram showing the actual positions of multiple exposure patterns on the wafer provided in the embodiments of this application; Figure 4 yes Figure 3 A schematic diagram showing the theoretical positions of multiple measurement patterns corresponding to multiple exposure patterns in the image; Figure 5 This is a structural block diagram of a calibration device for a lithography machine provided in an embodiment of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0022] The use of "applies to" or "configured to" in this application implies open and inclusive language, which does not exclude the applicability to or configuration to devices performing additional tasks or steps. Additionally, the use of "based on" implies openness and inclusivity, because processes, steps, calculations, or other actions "based on" one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0023] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0024] For newly built semiconductor manufacturing plants, the lack of high-precision, high-stability standard lithography machines and the absence of standard calibration wafers specifically used for calibrating and verifying lithography machines leads to exposure deviations in the lithography machines (such as the first lithography machine to arrive at the plant). These exposure deviations directly damage core precision indicators in semiconductor manufacturing, such as overlay accuracy and critical dimension uniformity.

[0025] Therefore, embodiments of this application provide a calibration method for a lithography machine, enabling rapid calibration of the lithography machine to be calibrated (such as the first lithography machine arriving at the factory) to a relatively reasonable position even in the absence of a standard lithography machine and standard calibration wafers. Please refer to... Figure 1 The diagram illustrates a flow chart of a lithography machine calibration method according to an embodiment of this application. It should be noted that while this specification provides the operational steps described in the embodiments or flowcharts, more or fewer operational steps may be included based on conventional or non-inventive methods. The order of steps listed in the embodiments is merely one possible execution order among many and does not represent the only possible execution order. In actual system or product execution, the methods shown in the embodiments or accompanying drawings can be executed sequentially or in parallel. Specifically, as shown... Figure 1 As shown, the method may include: S101, based on the exposure grid of the lithography machine to be calibrated, calculate the theoretical position data of multiple measurement patterns on the mask corresponding to the wafer respectively; the theoretical position data corresponding to each measurement pattern includes a first theoretical distance and a second theoretical distance, the first theoretical distance represents the distance to the wafer edge in the horizontal direction, and the second theoretical distance represents the distance to the wafer edge in the vertical direction.

[0026] Specifically, the exposure grid of the lithography machine to be calibrated is a virtual array of measurement points used by the lithography machine for positioning. In this embodiment, the parameters of the exposure grid include a step size and a grid shift. The step size defines the spacing of the measurement points, which can include the length in the horizontal direction (also known as the X-direction) and the length in the vertical direction (also known as the Y-direction). The grid shift defines the starting position offset of the entire measurement point array to ensure that the measurement points are aligned with the center of the wafer. The lithography machine to be calibrated can start from a starting point defined by the grid shift and automatically generate a virtual, neatly arranged array of measurement points, i.e., the exposure grid, on the wafer according to the intervals specified by the step size.

[0027] like Figure 2The diagram shows an exposure grid provided in an embodiment of this application, where the X direction is horizontal and the Y direction is vertical. The step size and grid shift of the exposure grid are shown in Table 1 below: Table 1

[0028] Based on the exposure grid of the lithography machine to be calibrated, the theoretical position data of multiple measurement patterns on the mask corresponding to the wafer are calculated. The theoretical position data of each measurement pattern includes a first theoretical distance from the edge of the wafer in the X direction and a second theoretical distance representing the distance from the edge of the wafer in the Y direction.

[0029] Specifically, for each measurement pattern on the mask, the theoretical coordinates of multiple key points on the wafer corresponding to that measurement pattern can be calculated based on the grid shift of the exposure grid and the size of the measurement pattern. These key points can include the intersection point where the exposure grid falls into the measurement pattern, the horizontal extension point of the cross, and the vertical extension point of the cross. The horizontal extension point is the intersection point extending horizontally from the intersection point to the wafer edge, and the vertical extension point is the intersection point extending vertically from the intersection point to the wafer edge. Furthermore, based on the theoretical coordinates of the intersection point, the horizontal extension point, and the vertical extension point, the first theoretical distance and the second theoretical distance corresponding to the measurement pattern can be calculated. The first theoretical distance is the difference between the theoretical abscissa of the horizontal extension point and the theoretical abscissa of the intersection point, and the second theoretical distance is the difference between the theoretical ordinate of the vertical extension point and the theoretical ordinate of the intersection point. Thus, the theoretical distances of each measurement pattern from the wafer edge in the X and Y directions can be obtained through these theoretical differences.

[0030] S103, the multiple measurement patterns on the photomask are exposed onto the wafer using the lithography machine to be calibrated, thereby obtaining multiple exposure patterns on the wafer.

[0031] It is understandable that multiple exposure patterns on the wafer correspond one-to-one with multiple measurement patterns on the mask, but there may be discrepancies in their positions.

[0032] S105, measure the actual position of each of the exposed patterns on the wafer to obtain measurement position data for each of the exposed patterns; the measurement position data includes a first measurement distance and a second measurement distance, the first measurement distance representing the distance from the edge of the wafer in the horizontal direction, and the second measurement distance representing the distance from the edge of the wafer in the vertical direction.

[0033] For example, for each exposure pattern, the actual coordinates of multiple key points on the wafer can be measured. These key points include the intersection point where the exposure grid falls into the exposure pattern, the horizontal extension point of the cross, and the vertical extension point of the cross. The horizontal extension point is the intersection point extending horizontally from the intersection point to the wafer edge, and the vertical extension point is the intersection point extending vertically from the intersection point to the wafer edge. Then, based on the actual coordinates of the intersection point, the horizontal extension point, and the vertical extension point, a first measurement distance and a second measurement distance corresponding to the exposure pattern are determined. The first measurement distance is the difference between the actual abscissa of the horizontal extension point and the actual abscissa of the intersection point, and the second measurement distance is the difference between the actual ordinate of the vertical extension point and the actual ordinate of the intersection point. Thus, the actual distances of each exposure pattern from the wafer edge in the X and Y directions can be obtained through these actual differences.

[0034] In practice, the actual coordinates of multiple key points on the wafer can be measured using OVL or other instruments that can record coordinates.

[0035] S107, based on the deviation between the first theoretical distance of each of the measured patterns and the first measured distance of the corresponding exposure pattern, and the deviation between the second theoretical distance of each of the measured patterns and the second measured distance of the corresponding exposure pattern, the exposure grid deviation is determined.

[0036] Specifically, the exposure grid deviation can include horizontal grid deviation (grid X deviation) and vertical grid deviation (grid Y deviation). Since the first theoretical distance and the first measured distance characterize the distance from the wafer edge in the horizontal direction, the horizontal grid deviation (grid X deviation) can be obtained based on the deviation between the first theoretical distance of each measurement pattern and the first measured distance of the corresponding exposure pattern. Since the second theoretical distance and the second measured distance characterize the distance from the wafer edge in the vertical direction, the vertical grid deviation (grid Y deviation) can be obtained based on the deviation between the second theoretical distance of each measurement pattern and the second measured distance of the corresponding exposure pattern.

[0037] In some embodiments, the plurality of measurement patterns include a first measurement pattern, a second measurement pattern, a third measurement pattern, and a fourth measurement pattern, wherein the first and second measurement patterns are distributed on one side of the horizontal direction, and the third and fourth measurement patterns are distributed on the other side of the horizontal direction; the first and third measurement patterns are distributed on one side of the vertical direction, and the second and fourth measurement patterns are distributed on the other side of the vertical direction.

[0038] Understandably, the multiple exposure patterns on the wafer include a first exposure pattern, a second exposure pattern, a third exposure pattern, and a fourth exposure pattern, which correspond to the aforementioned multiple measurement patterns, respectively.

[0039] Please see Figure 3 The diagram shows the actual locations of multiple exposure patterns on the wafer. Figure 4 The diagram shows the theoretical positions of the multiple measurement patterns corresponding to these multiple exposure patterns. For example... Figure 4 As shown, the first measurement pattern 1 and the second measurement pattern 2 are distributed on the same side of the X-axis, the third measurement pattern 3 and the fourth measurement pattern 4 are distributed on the other side of the X-axis, the first measurement pattern 1 and the third measurement pattern 3 are distributed on the same side of the Y-axis, and the second measurement pattern 2 and the fourth measurement pattern 4 are distributed on the other side of the Y-axis.

[0040] For example, the first measurement pattern, the second measurement pattern, the third measurement pattern, and the fourth measurement pattern can be symmetrically distributed, and the geometry of the first measurement pattern, the second measurement pattern, the third measurement pattern, and the fourth measurement pattern can be square. Their geometry can be the same or different.

[0041] in, Figure 3 The diagram illustrates three key points corresponding to each exposure pattern: the crossroads point O, the horizontal extension point H, and the vertical extension point V. Table 2 below shows... Figure 3 Examples of measurement location data for each exposure pattern are shown in Table 3 below. Figure 4 Examples of theoretical position data for each measurement graphic.

[0042] Table 2

[0043] Table 3

[0044] Here, "Size" represents the distance from the wafer edge. For example, OH represents the distance from the wafer edge in the horizontal X direction, which can be obtained by the difference between the X coordinate values ​​of point H and point O. OV represents the distance from the wafer edge in the vertical Y direction, which can be obtained by the difference between the Y coordinate values ​​of point V and point O.

[0045] Based on this, in some embodiments, the exposure grid deviation includes the horizontal grid deviation and the vertical grid deviation of the exposure grid, and the above step S107 may include the following when implemented: A first horizontal deviation is obtained based on the deviation between the first theoretical distance of the first target measurement pattern and the first measurement distance of the corresponding exposure pattern; a second horizontal deviation is obtained based on the deviation between the first theoretical distance of the second target measurement pattern and the first measurement distance of the corresponding exposure pattern; the first target measurement pattern and the second target measurement pattern are respectively the first measurement pattern and the second measurement pattern, or the first target measurement pattern and the second target measurement pattern are respectively the third measurement pattern and the fourth measurement pattern; The horizontal grid deviation of the exposure grid is determined based on the first horizontal deviation and the second horizontal deviation; A first vertical deviation is obtained based on the deviation between the first theoretical distance of the third target measurement pattern and the first measurement distance of the corresponding exposure pattern; a second vertical deviation is obtained based on the deviation between the first theoretical distance of the fourth target measurement pattern and the first measurement distance of the corresponding exposure pattern; the third target measurement pattern and the fourth target measurement pattern are respectively the first measurement pattern and the third measurement pattern, or the third target measurement pattern and the fourth target measurement pattern are respectively the second measurement pattern and the fourth measurement pattern; The vertical grid deviation of the exposure grid is determined based on the first vertical deviation and the second vertical deviation.

[0046] Specifically, based on the location data in Tables 2 and 3 above, and... Figure 3 and Figure 4 For example, we can obtain the following Table 4: Table 4

[0047] Wherein, OH (horizontal deviation) is the difference between OH (first measured distance) and OH (first theoretical distance); OV (vertical deviation) is the difference between OV (second theoretical distance) and OV (second measured distance).

[0048] Specifically, if the first target measurement pattern and the second target measurement pattern are respectively the first measurement pattern 1 and the second measurement pattern 2, the horizontal grid deviation of the exposure grid can be determined using the OH (horizontal deviation) corresponding to pattern 1 and the OH (horizontal deviation) corresponding to pattern 2 in Table 4. If the first target measurement pattern and the second target measurement pattern are respectively the third measurement pattern 3 and the fourth measurement pattern 4, the horizontal grid deviation of the exposure grid can be determined using the OH (horizontal deviation) corresponding to pattern 3 and the OH (horizontal deviation) corresponding to pattern 4 in Table 4.

[0049] If the third and fourth target measurement patterns are the first measurement pattern 1 and the third measurement pattern 3, respectively, the vertical grid deviation of the exposure grid can be determined using the OV (vertical deviation) corresponding to pattern 1 and the OV (vertical deviation) corresponding to pattern 3 in Table 4. If the third and fourth target measurement patterns are the second measurement pattern 2 and the fourth measurement pattern 4, respectively, the vertical grid deviation of the exposure grid can be determined using the OV (vertical deviation) corresponding to pattern 2 and the OV (vertical deviation) corresponding to pattern 4 in Table 4.

[0050] In some implementations, determining the horizontal grid deviation of the exposure grid based on the first horizontal deviation and the second horizontal deviation may include: determining half of the sum of the first horizontal deviation and the second horizontal deviation to obtain the horizontal grid deviation of the exposure grid; Determining the vertical grid deviation of the exposure grid based on the first vertical deviation and the second vertical deviation may include: determining half of the sum of the first vertical deviation and the second vertical deviation to obtain the vertical grid deviation of the exposure grid.

[0051] Specifically, taking the OH (horizontal deviation) corresponding to graph 1 as the first horizontal deviation and the OH (horizontal deviation) corresponding to graph 2 as the second horizontal deviation as an example, since graphs 1 and 2 are distributed on the same side of the X-axis and on different sides of the Y-axis, the first horizontal deviation corresponding to graph 1 and the second horizontal deviation corresponding to graph 2 are in opposite directions. Taking the average, we can calculate how much the entire exposure grid, or coordinate system, has been "stretched" or "compressed" in the X-direction. For example, the horizontal grid deviation of the exposure grid, i.e., grid X deviation = (OH (horizontal deviation) of graph 1 + OH (horizontal deviation) of graph 2) / 2 = (0.719 - 0.427) / 2 = 0.146 mm. Similarly, since patterns 3 and 4 are located on the same side of the X-axis and on different sides of the Y-axis, the horizontal grid deviation of the exposure grid can be calculated using the OH (horizontal deviation) corresponding to pattern 3 as the first horizontal deviation and the OH (horizontal deviation) corresponding to pattern 4 as the second horizontal deviation. That is, the horizontal grid deviation of the exposure grid is grid X deviation = (OH (horizontal deviation) of pattern 3 + OH (horizontal deviation) of pattern 4) / 2 = (0.082 + 0.21) / 2 = 0.146 mm.

[0052] Taking the OV (vertical deviation) corresponding to Figure 1 as the first vertical deviation and the OV (vertical deviation) corresponding to Figure 3 as the second vertical deviation as an example, since Figures 1 and 3 are distributed on different sides of the X-axis but on the same side, the first vertical deviation corresponding to Figure 1 and the second vertical deviation corresponding to Figure 3 are in opposite directions. Taking the average, we can calculate how much the entire exposure grid, or coordinate system, has been "stretched" or "compressed" in the Y-axis. For example, the vertical grid deviation of the exposure grid, i.e., grid Y deviation, = (OV (vertical deviation) of Figure 1 + OV (vertical deviation) of Figure 3) / 2 = (1.335 + 0.001) / 2 = 0.668 mm. Similarly, since Figures 2 and 4 are distributed on different sides of the X-axis but on the same side, the vertical grid deviation of the exposure grid can be calculated using the OV (vertical deviation) corresponding to Figure 2 as the first vertical deviation and the OV (vertical deviation) corresponding to Figure 4 as the second vertical deviation. That is, the vertical grid deviation of the exposure grid, i.e., gridY deviation = (OV (vertical deviation) of Figure 2 + OV (vertical deviation) of Figure 4)) / 2 = (0.922 + 0.421) / 2 = 0.671 mm.

[0053] Understandably, the horizontal grid deviation of each exposure grid can be averaged to obtain the average horizontal grid deviation. Similarly, the vertical grid deviation of each exposure grid can be averaged to obtain the average vertical grid deviation, thereby improving the accuracy of the exposure grid deviation.

[0054] S109, Based on the exposure grid deviation, the exposure grid of the lithography machine to be calibrated is compensated and calibrated.

[0055] Specifically, exposure grid deviation can be used to compensate for and calibrate parameters of the exposure grid, such as grid shift.

[0056] The technical solution described in this application is based on calculating the theoretical position data of multiple measurement patterns on the mask corresponding to the exposure grid of the lithography machine to be calibrated on the wafer. The theoretical position data corresponding to each measurement pattern includes a first theoretical distance representing the distance from the wafer edge in the horizontal direction and a second theoretical distance representing the distance from the wafer edge in the vertical direction. The lithography machine to be calibrated exposes the multiple measurement patterns on the mask onto the wafer to obtain multiple exposure patterns on the wafer. Then, the actual position of each exposure pattern on the wafer is measured to obtain the measurement position data of each exposure pattern. The measurement position data includes the first measurement data representing the distance from the wafer edge in the horizontal direction and the second measurement distance representing the distance from the wafer edge in the vertical direction. The exposure grid deviation is determined based on the deviation between the first theoretical distance of each measurement pattern and the first measurement distance of the corresponding exposure pattern, and the deviation between the second theoretical distance of each measurement pattern and the second measurement distance of the corresponding exposure pattern. The exposure grid deviation is then used to compensate and calibrate the exposure grid of the lithography machine to be calibrated, thereby enabling the lithography machine to be calibrated (such as the first lithography machine arriving at the factory) to be quickly calibrated to a relatively reasonable position even without a standard lithography machine and a standard calibration wafer.

[0057] Corresponding to the calibration methods for lithography machines provided in the above embodiments, this application also provides a calibration device for lithography machines. Since the calibration device for lithography machines provided in this application corresponds to the calibration methods for lithography machines provided in the above embodiments, the implementation methods of the aforementioned calibration methods for lithography machines are also applicable to the calibration device for lithography machines provided in this embodiment, and will not be described in detail in this embodiment.

[0058] Please see Figure 5 The diagram shows a structural block diagram of a lithography machine calibration device provided in an embodiment of this application. This device has the function of implementing the lithography machine calibration method described in the above-described method embodiments. Figure 5 As shown, the calibration device 500 of the lithography machine may include: The theoretical position calculation module 510 is configured to calculate the theoretical position data of multiple measurement patterns on the mask on the wafer based on the exposure grid of the lithography machine to be calibrated; the theoretical position data corresponding to each measurement pattern includes a first theoretical distance and a second theoretical distance, the first theoretical distance representing the distance to the wafer edge in the horizontal direction, and the second theoretical distance representing the distance to the wafer edge in the vertical direction. Exposure module 520 is configured to expose the plurality of measurement patterns on the mask onto the wafer using the lithography machine to be calibrated, thereby obtaining a plurality of exposure patterns on the wafer; The position measurement module 530 is configured to measure the actual position of each of the exposed patterns on the wafer to obtain measurement position data for each of the exposed patterns; the measurement position data includes a first measurement distance and a second measurement distance, the first measurement distance representing the distance from the edge of the wafer in the horizontal direction, and the second measurement distance representing the distance from the edge of the wafer in the vertical direction; The grid deviation determination module 540 is configured to determine the exposure grid deviation based on the deviation between the first theoretical distance of each of the measured patterns and the first measured distance of the corresponding exposure pattern, and the deviation between the second theoretical distance of each of the measured patterns and the second measured distance of the corresponding exposure pattern. The calibration module 550 is configured to perform compensation calibration on the exposure grid of the lithography machine to be calibrated based on the exposure grid deviation.

[0059] In some embodiments, the position measurement module 530 is specifically configured to measure the actual coordinates of multiple key points on the wafer for each exposure pattern; the multiple key points include the intersection point where the exposure grid falls into the exposure pattern, the horizontal extension point of the cross, and the vertical extension point of the cross, wherein the horizontal extension point is the intersection point extending from the intersection point along the horizontal direction to the edge of the wafer, and the vertical extension point is the intersection point extending from the intersection point along the vertical direction to the edge of the wafer; based on the actual coordinates of the intersection point, the actual coordinates of the horizontal extension point, and the actual coordinates of the vertical extension point, a first measurement distance and a second measurement distance corresponding to the exposure pattern are determined.

[0060] In some embodiments, the theoretical position calculation module 510 is specifically configured to, for each measurement pattern, calculate the theoretical coordinates of the plurality of key points on the wafer based on the exposure grid of the lithography machine to be calibrated; and determine the first theoretical distance and the second theoretical distance corresponding to the measurement pattern based on the theoretical coordinates of the cross intersection point, the theoretical coordinates of the horizontal extension point of the cross, and the theoretical coordinates of the vertical extension point of the cross.

[0061] In some embodiments, the plurality of measurement patterns include a first measurement pattern, a second measurement pattern, a third measurement pattern, and a fourth measurement pattern, wherein the first and second measurement patterns are distributed on one side of the horizontal direction, and the third and fourth measurement patterns are distributed on the other side of the horizontal direction; the first and third measurement patterns are distributed on one side of the vertical direction, and the second and fourth measurement patterns are distributed on the other side of the vertical direction.

[0062] In some embodiments, the grid deviation determination module 540 includes: The horizontal deviation determination module is configured to obtain a first horizontal deviation based on the deviation between a first theoretical distance of a first target measurement pattern and a first measurement distance of a corresponding exposure pattern; and to obtain a second horizontal deviation based on the deviation between a first theoretical distance of a second target measurement pattern and a first measurement distance of a corresponding exposure pattern; wherein the first target measurement pattern and the second target measurement pattern are respectively the first measurement pattern and the second measurement pattern, or the first target measurement pattern and the second target measurement pattern are respectively the third measurement pattern and the fourth measurement pattern; A horizontal grid deviation determination module is configured to determine the horizontal grid deviation of the exposure grid based on the first horizontal deviation and the second horizontal deviation; The vertical deviation determination module is configured to obtain a first vertical deviation based on the deviation between a first theoretical distance of a third target measurement pattern and a first measurement distance of a corresponding exposure pattern; and to obtain a second vertical deviation based on the deviation between a first theoretical distance of a fourth target measurement pattern and a first measurement distance of a corresponding exposure pattern; wherein the third target measurement pattern and the fourth target measurement pattern are respectively the first measurement pattern and the third measurement pattern, or the third target measurement pattern and the fourth target measurement pattern are respectively the second measurement pattern and the fourth measurement pattern; A vertical grid deviation determination module is configured to determine the vertical grid deviation of the exposure grid based on the first vertical deviation and the second vertical deviation; The exposure grid deviation includes the horizontal grid deviation and the vertical grid deviation of the exposure grid.

[0063] In some implementations, the horizontal grid deviation determination module is specifically configured to determine half of the sum of the first horizontal deviation and the second horizontal deviation to obtain the horizontal grid deviation of the exposure grid; The vertical deviation determination module is specifically configured to determine half of the sum of the first vertical deviation and the second vertical deviation to obtain the vertical grid deviation of the exposure grid.

[0064] It should be noted that the apparatus provided in the above embodiments is only illustrated by the division of the above functional modules when implementing its functions. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the apparatus and method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0065] This application also provides a lithography machine, including a controller and a memory. The memory stores computer instructions, which, when executed by the controller, implement any of the calibration methods for the lithography machine in this application.

[0066] In the embodiments of this application, the storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM), etc.

[0067] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0068] The calibration method, apparatus, and lithography machine of the lithography machine provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A calibration method for a photolithography machine, characterized in that, include: Based on the exposure grid of the lithography machine to be calibrated, the theoretical position data corresponding to multiple measurement patterns on the mask on the wafer are calculated respectively; the theoretical position data corresponding to each measurement pattern includes a first theoretical distance and a second theoretical distance, the first theoretical distance represents the distance from the wafer edge in the horizontal direction, and the second theoretical distance represents the distance from the wafer edge in the vertical direction; The multiple measurement patterns on the photomask are exposed onto the wafer using the lithography machine to be calibrated, resulting in multiple exposure patterns on the wafer; The actual position of each of the exposed patterns on the wafer is measured to obtain measurement position data for each of the exposed patterns; the measurement position data includes a first measurement distance and a second measurement distance, wherein the first measurement distance represents the distance from the edge of the wafer in the horizontal direction, and the second measurement distance represents the distance from the edge of the wafer in the vertical direction; The exposure grid deviation is determined based on the deviation between the first theoretical distance of each of the measured patterns and the first measured distance of the corresponding exposure pattern, and the deviation between the second theoretical distance of each of the measured patterns and the second measured distance of the corresponding exposure pattern. Based on the exposure grid deviation, the exposure grid of the lithography machine to be calibrated is compensated and calibrated.

2. The method according to claim 1, characterized in that, The measurement of the actual position of each of the exposed patterns on the wafer, to obtain the measurement position data of each of the exposed patterns, includes: For each of the exposure patterns, the actual coordinates of multiple key points on the wafer are measured; the multiple key points include the intersection point where the exposure grid falls into the exposure pattern, the horizontal extension point of the cross, and the vertical extension point of the cross, wherein the horizontal extension point of the cross is the intersection point extending from the intersection point along the horizontal direction to the edge of the wafer, and the vertical extension point of the cross is the intersection point extending from the intersection point along the vertical direction to the edge of the wafer. Based on the actual coordinates of the cross intersection point, the actual coordinates of the horizontal extension point of the cross, and the actual coordinates of the vertical extension point of the cross, the first measurement distance and the second measurement distance corresponding to the exposure pattern are determined.

3. The method according to claim 2, characterized in that, The calculation of the theoretical position data on the wafer corresponding to multiple measurement patterns on the mask, based on the exposure grid of the lithography machine to be calibrated, includes: For each of the measurement patterns, based on the exposure grid of the lithography machine to be calibrated, the theoretical coordinates of the multiple key points on the wafer are calculated respectively; Based on the theoretical coordinates of the cross intersection point, the theoretical coordinates of the horizontal extension point of the cross, and the theoretical coordinates of the vertical extension point of the cross, the first theoretical distance and the second theoretical distance corresponding to the measured pattern are determined.

4. The method according to any one of claims 1 to 3, characterized in that, The plurality of measurement patterns include a first measurement pattern, a second measurement pattern, a third measurement pattern, and a fourth measurement pattern. The first and second measurement patterns are distributed on one side of the horizontal direction, and the third and fourth measurement patterns are distributed on the other side of the horizontal direction. The first and third measurement patterns are distributed on one side of the vertical direction, and the second and fourth measurement patterns are distributed on the other side of the vertical direction.

5. The method according to claim 4, characterized in that, The determination of exposure grid deviation based on the deviation between the first theoretical distance of each of the measured patterns and the first measured distance of the corresponding exposure pattern, and the deviation between the second theoretical distance of each of the measured patterns and the second measured distance of the corresponding exposure pattern, includes: A first horizontal deviation is obtained based on the deviation between the first theoretical distance of the first target measurement pattern and the first measurement distance of the corresponding exposure pattern; a second horizontal deviation is obtained based on the deviation between the first theoretical distance of the second target measurement pattern and the first measurement distance of the corresponding exposure pattern; the first target measurement pattern and the second target measurement pattern are respectively the first measurement pattern and the second measurement pattern, or the first target measurement pattern and the second target measurement pattern are respectively the third measurement pattern and the fourth measurement pattern; The horizontal grid deviation of the exposure grid is determined based on the first horizontal deviation and the second horizontal deviation; A first vertical deviation is obtained based on the deviation between the second theoretical distance of the third target measurement pattern and the second measurement distance of the corresponding exposure pattern; a second vertical deviation is obtained based on the deviation between the second theoretical distance of the fourth target measurement pattern and the second measurement distance of the corresponding exposure pattern; the third target measurement pattern and the fourth target measurement pattern are respectively the first measurement pattern and the third measurement pattern, or the third target measurement pattern and the fourth target measurement pattern are respectively the second measurement pattern and the fourth measurement pattern; The vertical grid deviation of the exposure grid is determined based on the first vertical deviation and the second vertical deviation; The exposure grid deviation includes the horizontal grid deviation and the vertical grid deviation of the exposure grid.

6. The method according to claim 5, characterized in that, Determining the horizontal grid deviation of the exposure grid based on the first horizontal deviation and the second horizontal deviation includes: The horizontal grid deviation of the exposure grid is obtained by determining half of the sum of the first horizontal deviation and the second horizontal deviation; The determination of the vertical grid deviation of the exposure grid based on the first vertical deviation and the second vertical deviation includes: The vertical grid deviation of the exposure grid is obtained by determining half of the sum of the first vertical deviation and the second vertical deviation.

7. A calibration device for a lithography machine, characterized in that, The device includes: The theoretical position calculation module is configured to calculate the theoretical position data corresponding to multiple measurement patterns on the mask on the wafer based on the exposure grid of the lithography machine to be calibrated. The theoretical position data corresponding to each measurement pattern includes a first theoretical distance and a second theoretical distance. The first theoretical distance represents the distance to the wafer edge in the horizontal direction, and the second theoretical distance represents the distance to the wafer edge in the vertical direction. An exposure module is configured to expose the plurality of measurement patterns on the mask onto the wafer using the lithography machine to be calibrated, thereby obtaining a plurality of exposure patterns on the wafer; A position measurement module is configured to measure the actual position of each of the exposed patterns on the wafer to obtain measurement position data for each of the exposed patterns; the measurement position data includes a first measurement distance and a second measurement distance, the first measurement distance representing the distance from the wafer edge in the horizontal direction, and the second measurement distance representing the distance from the wafer edge in the vertical direction; The grid deviation determination module is configured to determine the exposure grid deviation based on the deviation between the first theoretical distance of each of the measured patterns and the first measured distance of the corresponding exposure pattern, and the deviation between the second theoretical distance of each of the measured patterns and the second measured distance of the corresponding exposure pattern. The calibration module is configured to compensate and calibrate the exposure grid of the lithography machine to be calibrated based on the exposure grid deviation.

8. The apparatus according to claim 7, characterized in that, The plurality of measurement patterns include a first measurement pattern, a second measurement pattern, a third measurement pattern, and a fourth measurement pattern. The first and second measurement patterns are distributed on one side of the horizontal direction, and the third and fourth measurement patterns are distributed on the other side of the horizontal direction. The first and third measurement patterns are distributed on one side of the vertical direction, and the second and fourth measurement patterns are distributed on the other side of the vertical direction.

9. The apparatus according to claim 8, characterized in that, The grid deviation determination module includes: The horizontal deviation determination module is configured to obtain a first horizontal deviation based on the deviation between a first theoretical distance of a first target measurement pattern and a first measurement distance of a corresponding exposure pattern; and to obtain a second horizontal deviation based on the deviation between a first theoretical distance of a second target measurement pattern and a first measurement distance of a corresponding exposure pattern; wherein the first target measurement pattern and the second target measurement pattern are respectively the first measurement pattern and the second measurement pattern, or the first target measurement pattern and the second target measurement pattern are respectively the third measurement pattern and the fourth measurement pattern; A horizontal grid deviation determination module is configured to determine the horizontal grid deviation of the exposure grid based on the first horizontal deviation and the second horizontal deviation; The vertical deviation determination module is configured to obtain a first vertical deviation based on the deviation between a first theoretical distance of a third target measurement pattern and a first measurement distance of a corresponding exposure pattern; and to obtain a second vertical deviation based on the deviation between a first theoretical distance of a fourth target measurement pattern and a first measurement distance of a corresponding exposure pattern; wherein the third target measurement pattern and the fourth target measurement pattern are respectively the first measurement pattern and the third measurement pattern, or the third target measurement pattern and the fourth target measurement pattern are respectively the second measurement pattern and the fourth measurement pattern; A vertical grid deviation determination module is configured to determine the vertical grid deviation of the exposure grid based on the first vertical deviation and the second vertical deviation; The exposure grid deviation includes the horizontal grid deviation and the vertical grid deviation of the exposure grid.

10. A lithography machine, comprising a controller and a memory, wherein the memory stores computer instructions, characterized in that, When the computer instructions are executed by the controller, they implement the calibration method of the lithography machine as described in any one of claims 1 to 6.

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