Photoetching method

Abstract

The invention relates to a photoetching method which comprises the steps that a compatible alignment mark is formed on a test wafer, the compatible alignment mark can be identified in first photoetching equipment and can also be identified in second photoetching equipment, the first photoetching equipment is used for carrying out a first photoetching process, and the second photoetching equipment is used for carrying out a second photoetching process; detecting the compatible alignment mark through first photoetching equipment to obtain first data, and detecting the compatible alignment mark through second photoetching equipment to obtain second data; according to the first data and the second data, obtaining a detection position error of the first photoetching equipment and the second photoetching equipment; performing a first photoetching process on the process wafer through first photoetching equipment, and forming a first alignment mark on the process wafer; and detecting a preliminary mark position of the first alignment mark through second photoetching equipment, obtaining an alignment mark position according to an error between the preliminary mark position and the detection position, and carrying out a second photoetching process on the process wafer subjected to the first photoetching process based on the alignment mark position.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a photolithography method. Background Art

[0002] Photolithography is a common process in semiconductor processing. Photolithography can include optical photolithography and electron beam photolithography. Different photolithography processes can be processed by different types of photolithography equipment.

[0003] However, different photolithography equipment has different principles for detecting alignment marks, so different photolithography processes are difficult to use simultaneously in actual processing. Summary of the invention

[0004] Based on this, it is necessary to provide a lithography method that uses two lithography processes to address the above technical issues.

[0005] The present application provides a photolithography method, the method comprising:

[0006] forming a compatible alignment mark on a test wafer, wherein the compatible alignment mark can be recognized in a first lithography apparatus and can also be recognized in a second lithography apparatus, wherein the first lithography apparatus is used to perform a first lithography process, and the second lithography apparatus is used to perform a second lithography process, and the first lithography process and the second lithography process are lithography processes of different types;

[0007] Probing the compatible alignment mark by the first lithography device to obtain first data, and probing the compatible alignment mark by the second lithography device to obtain second data;

[0008] Acquire a detection position error between the first photolithography device and the second photolithography device according to the first data and the second data;

[0009] Performing a first photolithography process on the process wafer by a first photolithography device to form a first alignment mark on the process wafer;

[0010] The preliminary mark position of the first alignment mark is detected by a second photolithography device, and the alignment mark position is obtained according to the error between the preliminary mark position and the detected position, and a second photolithography process is performed on the process wafer that has undergone the first photolithography process based on the alignment mark position.

[0011] The above-mentioned lithography method forms a compatible alignment mark that can be recognized by both the first lithography device and the second lithography device on the test wafer, and uses the first lithography device and the second lithography device to detect the compatible alignment mark, thereby obtaining the detection position error, thereby eliminating or reducing the position error caused by different detection principles of lithography devices of different models, and increasing the overlay accuracy of the two lithography devices. At this time, the first lithography process and the second lithography process can be used in combination.

[0012] In one embodiment, one of the first lithography apparatus and the second lithography apparatus is an optical lithography apparatus, and the other is an electron beam lithography apparatus.

[0013] The compatible alignment marks include:

[0014] A plurality of periodically arranged first lines, wherein the first lines extend along a first direction;

[0015] A plurality of periodically arranged second lines, wherein the second lines extend along a second direction and intersect the first lines.

[0016] In one embodiment, the compatible alignment mark is a centrally symmetrical structure.

[0017] In one embodiment, the first direction is perpendicular to the second direction.

[0018] The compatible alignment marks include a line group L1, a line group L2, a line group L3, and a line group L4, wherein the line group L1, the line group L2, the line group L3, and the line group L4 each include the plurality of periodically arranged first lines and the plurality of periodically arranged second lines,

[0019] The line group L1 is centrally symmetrical with the line group L3, the line group L2 is centrally symmetrical with the line group L4, the line group L1 is axially symmetrical with the line group L2, and the line group L3 is axially symmetrical with the line group L4.

[0020] In one embodiment, the first direction is not perpendicular to the second direction.

[0021] The compatible alignment marks include line group L5, line group L6, line group L7, line group L8, line group L9, line group L10, line group L11 and line group L12,

[0022] The line group L5 is centrally symmetrical with the line group L9, and both include the plurality of periodically arranged first lines and the plurality of periodically arranged second lines.

[0023] The line group L7 is centrally symmetrical with the line group L11, and both include a plurality of periodically arranged third lines and a plurality of periodically arranged fourth lines, the third lines extend along a third direction, the fourth lines extend along a fourth direction, and the third lines intersect with the fourth lines.

[0024] The line group L6 is centrally symmetrical with the line group L10, and both include a plurality of periodically arranged second lines and a plurality of periodically arranged third lines, wherein the second lines intersect with the third lines.

[0025] The line group L8 is centrally symmetrical to the line group L12 , and both include a plurality of periodically arranged first lines and a plurality of periodically arranged fourth lines, wherein the first lines intersect with the fourth lines.

[0026] In one embodiment, forming a compatible alignment mark on a test wafer includes:

[0027] A compatible alignment mark groove or a compatible alignment mark strip is formed on the test wafer.

[0028] In one embodiment, the first data includes a first coordinate, the first coordinate includes a first X coordinate and a first Y coordinate, the second data includes a second coordinate, the second coordinate includes a second X coordinate and a second Y coordinate,

[0029] Acquiring a detection position error between the first lithography device and the second lithography device according to the first data and the second data includes:

[0030] Obtain a first error according to the first X-coordinate and the second X-coordinate;

[0031] A second error is obtained according to the first Y coordinate and the second Y coordinate.

[0032] In one embodiment, detecting the compatible alignment mark by the first lithography device to obtain first data, and detecting the compatible alignment mark by the second lithography device to obtain second data, comprises:

[0033] Performing multiple detections on the compatible alignment mark by the first photolithography device to obtain multiple first coordinates;

[0034] Performing multiple detections on the compatible alignment mark by the second photolithography device to obtain multiple second coordinates, where the second coordinates correspond to the first coordinates one by one;

[0035] Acquiring a first error according to the first X-coordinate and the second X-coordinate includes:

[0036] Establishing a third coordinate system about the first X coordinate and the second X coordinate;

[0037] filtering the first coordinate and the second coordinate according to the third coordinate system;

[0038] A linear fit is performed on the filtered first X-coordinate and the second X-coordinate to obtain a first intercept, where the first intercept is the first error.

[0039] In one embodiment, detecting the compatible alignment mark by the first lithography device to obtain first data, and detecting the compatible alignment mark by the second lithography device to obtain second data, comprises:

[0040] Performing multiple detections on the compatible alignment mark by the first photolithography device to obtain multiple first coordinates;

[0041] Performing multiple detections on the compatible alignment mark by the second photolithography device to obtain multiple second coordinates, where the second coordinates correspond to the first coordinates one by one;

[0042] Acquiring a second error according to the first Y coordinate and the second Y coordinate includes:

[0043] Establishing a fourth coordinate system about the first Y coordinate and the second Y coordinate;

[0044] filtering the first coordinate and the second coordinate according to the fourth coordinate system;

[0045] A linear fit is performed on the filtered first Y coordinate and the second Y coordinate to obtain a second intercept, where the second intercept is the second error.

[0046] In one embodiment, the first alignment mark is of the same type as the compatible alignment mark. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of a photolithography method provided in one embodiment;

[0048] Figure 2 A schematic diagram of the structure of a compatible alignment mark provided in an embodiment;

[0049] Figure 3 A schematic diagram of the structure of a compatible alignment mark provided in yet another embodiment;

[0050] Figure 4 A schematic diagram of linear fitting in a third coordinate system provided in one embodiment;

[0051] Figure 5A schematic diagram of linear fitting in a third coordinate system provided in another embodiment;

[0052] Figure 6 It is a schematic diagram of linear fitting in a fourth coordinate system provided in one embodiment.

[0053] Explanation of the reference numerals: 10 - first line, 20 - second line, 30 - third line, 40 - fourth line. DETAILED DESCRIPTION

[0054] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs.

[0056] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0057] In one embodiment, see Figure 1 , providing a photolithography method, comprising:

[0058] Step S100, forming a compatible alignment mark on the test wafer, the compatible alignment mark can be recognized in a first lithography device and can also be recognized in a second lithography device, the first lithography device is used to perform a first lithography process, the second lithography device is used to perform a second lithography process, the first lithography process and the second lithography process are different types of lithography processes;

[0059] Step S200, detecting the compatible alignment mark by a first photolithography device to obtain first data, and detecting the compatible alignment mark by a second photolithography device to obtain second data;

[0060] Step S300, obtaining a detection position error between a first lithography device and a second lithography device according to the first data and the second data;

[0061] Step S400, performing a first photolithography process on the process wafer by using a first photolithography device to form a first alignment mark on the process wafer;

[0062] Step S500, detecting a preliminary mark position of the first alignment mark by a second photolithography device, obtaining an alignment mark position according to an error between the preliminary mark position and the detected position, and performing a second photolithography process on the process wafer that has undergone the first photolithography process based on the alignment mark position.

[0063] In step S100, the materials of the test wafer and the process wafer may include but are not limited to silicon materials. As an example, the test wafer may not have a film layer or structure formed by a process, and the process wafer may have a film layer or structure formed by a process. In other examples, the process wafer may not have a film layer or structure formed by a process, which is not limited here.

[0064] A compatible alignment mark is formed on the test wafer, and the compatible alignment mark can be recognized by the first photolithography device and can also be recognized by the second photolithography device.

[0065] The first lithography device can perform a first lithography process, and the second lithography device can perform a second lithography process. The first lithography process and the second lithography process are lithography processes of different types, and the first lithography device and the second lithography device are lithography devices of different models. The first lithography device and the second lithography device have different detection principles for alignment marks. Therefore, when the first lithography device and the second lithography device detect the same alignment mark, the mark positions of the alignment marks obtained by the two devices may be different.

[0066] In step S200, a first photolithography device is used to detect the compatible alignment mark to obtain first data thereof. The first data may be position data of the compatible alignment mark.

[0067] The number of times the first lithography device performs detection is not limited here, and can be set according to actual needs. For example, the number of times the detection can be 50 to 150 times. Specifically, the number of times the detection can be 100 times.

[0068] The second photolithography device is used to detect the compatible alignment mark to obtain second data thereof. The second data may be position data of the compatible alignment mark.

[0069] The number of times the second lithography device performs detection is not limited here, and can be set according to actual needs. For example, the number of times of detection can be 50 to 150 times. Specifically, the number of detection can be 100 times.

[0070] In step S300, a detection position error between a first lithography device and a second lithography device is obtained according to the first data and the second data.

[0071] In step S400 , a first photolithography process is performed on a process wafer using a first photolithography device to form a first alignment mark on the process wafer.

[0072] As an example, the first alignment mark can use the same type of alignment mark as the compatible alignment mark. When both use the same type of alignment mark, when the detection position error obtained based on the test wafer is applied to the second photolithography process of the process wafer, the influence of different types of alignment marks on the second photolithography process can be eliminated.

[0073] Of course, in other examples, the first alignment mark and the compatible alignment mark may also be different types of alignment marks, which is not limited here.

[0074] Meanwhile, the first alignment mark can be recognized by both the first photolithography apparatus and the second photolithography apparatus. Alternatively, the first alignment mark can also be recognized only by the second photolithography apparatus.

[0075] In step S500, a preliminary mark position of the first alignment mark is detected using a second photolithography device, and an alignment mark position of the second photolithography device is obtained through an error between the preliminary mark position and the detected position, and a second photolithography process is performed on the process wafer through the alignment mark position.

[0076] In this embodiment, a compatible alignment mark that can be recognized by both the first photolithography apparatus and the second photolithography apparatus is formed on the test wafer, and the first photolithography apparatus and the second photolithography apparatus are used to detect the compatible alignment mark, thereby obtaining a detection position error, thereby eliminating or reducing the position error caused by different detection principles of photolithography apparatuses of different models, and increasing the overlay accuracy of the two photolithography apparatuses. At this time, the first photolithography process and the second photolithography process can be used in combination.

[0077] In one embodiment, the first lithography apparatus is an optical lithography apparatus, the second lithography apparatus is an electron beam lithography apparatus, and the compatible alignment marks include:

[0078] A plurality of periodically arranged first lines 10, wherein the first lines 10 extend along a first direction;

[0079] A plurality of periodically arranged second lines 20 extend along a second direction, and the second lines 20 intersect with the first lines 10 .

[0080] There can be multiple first lines 10, where multiple means two or more. The first lines 10 can be periodically arranged, and it can be understood that the distances between the first lines 10 are equal. The length of the first lines 10 can be any value, which is not limited here.

[0081] There can be multiple second lines 20, where multiple means two or more. The second lines 20 can be periodically arranged, and it can be understood that the distances between the second lines 20 are equal. The length of the second lines 20 can be any value, which is not limited here.

[0082] Of course, the lengths of the first lines 10 and the second lines 20 may be equal or different. The distances between the first lines 10 and the distances between the second lines 20 may be equal or different.

[0083] At this time, on the one hand, the compatible alignment mark can be provided with a plurality of periodically arranged first lines 10 and a plurality of periodically arranged second lines 20, so that it can be recognized by the optical lithography equipment, thereby obtaining the first data of the compatible alignment mark in the first coordinate system. At this time, the first coordinate system is the coordinate system of the optical lithography equipment.

[0084] On the other hand, the compatible alignment mark can be set to intersect the first line 10 and the second line 20. At this time, the extension direction of the first line 10 also intersects with the extension direction of the second line 20, that is, the first direction intersects with the second direction. Therefore, the compatible alignment mark can be recognized by the electron beam lithography device, and then the second data of the compatible alignment mark in the second coordinate system is obtained. At this time, the second coordinate system is the coordinate system of the electron beam lithography device.

[0085] Meanwhile, when the compatible alignment mark is detected by using the optical lithography equipment, it may specifically include: firstly, the test wafer is moved, and then the position of the compatible alignment mark is detected by using ultraviolet laser.

[0086] The area of ​​the compatible alignment mark can be larger than the spot size of the UV laser, and can be detected by the UV laser, that is, recognized by the optical lithography equipment. As an example, the area of ​​the compatible alignment mark can be larger than 40 μm 2 .

[0087] In this embodiment, the compatible alignment mark can be recognized by both the photolithography equipment and the electron beam lithography equipment. The above-mentioned compatible alignment mark is formed on the test wafer, and the optical photolithography equipment and the electron beam lithography equipment are used to detect the compatible alignment mark, and then the detection position error is obtained, so that the position error caused by the different detection principles of the optical photolithography equipment and the electron beam lithography equipment can be eliminated or reduced, and the overlay accuracy between the optical photolithography equipment and the electron beam lithography equipment is increased. At this time, the optical photolithography process and the electron beam process can be used in combination.

[0088] Therefore, the photolithography process using the photolithography method can have the advantages of high yield of the optical photolithography process and high resolution of the electron beam photolithography process, thereby achieving a smaller line width.

[0089] In one embodiment, the compatible alignment mark may be a centrally symmetrical structure. In this case, the centrally symmetrical compatible alignment mark can make the mark position acquired by the electron beam lithography equipment detecting the compatible mark more accurate.

[0090] In one embodiment, see Figure 2 , the first direction is perpendicular to the second direction. At this time, the angle between the first direction and the second direction is a right angle.

[0091] Meanwhile, the compatible alignment marks may include line group L1, line group L2, line group L3 and line group L4, and line group L1, line group L2, line group L3 and line group L4 all include a plurality of periodically arranged first lines 10 and a plurality of periodically arranged second lines 20. Among them, line group L1 is centrally symmetrical with line group L3, line group L2 is centrally symmetrical with line group L4, line group L1 is axially symmetrical with line group L2, and line group L3 is axially symmetrical with line group L4. After the first lines 10 and the second lines 20 of line group L1, line group L2, line group L3 and line group L4 intersect, the first lines 10 no longer extend along the first direction, and the second lines 20 no longer extend along the second direction.

[0092] At this time, the first direction and the second direction are perpendicular to each other, and the first data can be acquired step by step. First, the Y coordinate of the first data is acquired according to the first line 10 , and then the X coordinate of the first data is acquired according to the second line 20 .

[0093] In one embodiment, see Figure 3 , the first direction and the second direction may not be perpendicular. In this case, the angle between the first direction and the second direction may be an acute angle.

[0094] The compatible alignment marks may include a line group L5, a line group L6, a line group L7, a line group L8, a line group L9, a line group L10, a line group L11, and a line group L12.

[0095] Meanwhile, the line group L5 is centrally symmetrical to the line group L9, and both include a plurality of periodically arranged first lines 10 and a plurality of periodically arranged second lines 20. After the first lines 10 intersect the second lines 20, the two no longer extend along their extension direction.

[0096] Meanwhile, the line group L7 is centrally symmetrical with the line group L11, and both include a plurality of periodically arranged third lines 30 and a plurality of periodically arranged fourth lines 40. The third lines 30 extend along the third direction, and the fourth lines 40 extend along the fourth direction. The third lines 30 and the fourth lines 40 intersect, and after the two intersect, they no longer extend along their extension directions. The third direction intersects with the fourth direction.

[0097] The third direction and the fourth direction may not be perpendicular. In this case, in the line group L7 and the line group L11, the angle between the third line 30 and the fourth line 40 may be an acute angle.

[0098] The included angle between the third line 30 and the fourth line 40 in the line group L7 and the included angle between the first line 10 and the second line 20 in the line group L5 may be the same as or different from each other.

[0099] Meanwhile, the line group L6 is centrally symmetrical to the line group L10, and both include a plurality of periodically arranged second lines 20 and a plurality of periodically arranged third lines 30. After the second lines 20 intersect the third lines 30, the two no longer extend along their extension direction.

[0100] The sum of the angle between the first line 10 and the second line 20 in the line group L5 and the angle between the second line 20 and the third line 30 in the line group L6 may be equal to 90°. Of course, the sum of the two angles may not be equal to 90°.

[0101] Meanwhile, the line group L8 is centrally symmetrical to the line group L12, and both include a plurality of periodically arranged first lines 10 and a plurality of periodically arranged fourth lines 40. After the first lines 10 intersect with the fourth lines 40, the two no longer extend along their extension direction.

[0102] In this embodiment, the first direction of the compatible alignment mark is not perpendicular to the second direction. At this time, when the first data of the compatible alignment mark is acquired by the optical lithography device, the X coordinate and the Y coordinate of the first data can be acquired simultaneously, making the acquisition of the first data more convenient and quick.

[0103] It is understandable that in the above embodiment, the "first line 10", "second line 20", "third line 30" and "fourth line 40" are distinguished by direction. Lines located in different directions are named differently, and lines located in the same direction are named the same. For example, the first line 10 and the second line 20 in the line group L5 are named differently because they extend along the first direction and the second direction respectively. For another example, the first line 10 in the line group L5 and the first line 10 in the line group L12 are both named the first line 10 because they extend along the first direction.

[0104] In one embodiment, step S100 includes:

[0105] Step S110 , forming a compatible alignment mark groove or a compatible alignment mark strip on the test wafer.

[0106] As an example, the compatible alignment mark groove may be formed by etching, and the groove depth of the compatible alignment mark groove may be 158.25 nm.

[0107] A compatible alignment mark strip is formed on the test wafer. Specifically, a compatible alignment mark material layer may be deposited on the test wafer and then etched to form the compatible alignment mark strip.

[0108] After forming the compatible alignment mark groove or the compatible alignment mark strip on the test wafer, the test wafer can also be reworked to remove the compatible alignment mark groove or the compatible alignment mark strip thereon. The reworked test wafer can also be used as a process wafer. Of course, the test wafer may not be reworked.

[0109] In one embodiment, the first data includes a first coordinate, the first coordinate includes a first X coordinate and a first Y coordinate, the second data includes a second X coordinate and a second Y coordinate, and step S300 includes:

[0110] Step S310, obtaining a first error according to the first X coordinate and the second X coordinate;

[0111] Step S320, obtaining a second error according to the first Y coordinate and the second Y coordinate.

[0112] In step S310, as an example, a plurality of first coordinates can be obtained by performing multiple detections on the compatible alignment mark through the first lithography device; a plurality of second coordinates can also be obtained by performing multiple detections on the compatible alignment mark through the second lithography device, where multiple means two or more than two, wherein the first coordinates and the second coordinates have a one-to-one correspondence and are equal in number.

[0113] When obtaining the first error according to the first X coordinate and the second X coordinate, a third coordinate system about the first X coordinate and the second X coordinate may be first established. Specifically, the first X coordinate may be used as the Y axis of the third coordinate system, and the second X coordinate may be used as the X axis of the third coordinate system.

[0114] Then, according to the third coordinate system, the first coordinate and the second coordinate are filtered. Specifically, the standard deviation method or the box plot method can be used for filtering. First, the discrete points in the third coordinate system are found. Then the first X coordinate and the second X coordinate corresponding to the discrete points are found. Then the first X coordinate and the second X coordinate are filtered out. At the same time, the first Y coordinate and the second Y coordinate corresponding to the first X coordinate and the second X coordinate are also filtered, so as to filter the first coordinate and the second coordinate.

[0115] Finally, a linear fit is performed on the filtered first X coordinate and the second X coordinate to obtain a first intercept, which is the first error.

[0116] The linear fitting of the first X coordinate and the second X coordinate includes performing correlation analysis based on each scattered point in the third coordinate system. When the correlation coefficient is greater than a preset value, it can be considered that the first X coordinate and the second X coordinate have a high correlation. The preset value can be selected according to actual needs, for example, it can be 0.8.

[0117] As an example, when linear fitting is performed on the first X coordinate and the second X coordinate, the linear relationship y1=ax1+b and the correlation coefficient R can be obtained. 2 When the correlation coefficient R 2 When the correlation coefficient R is greater than the preset value, b is directly used as the first intercept. 2 When the value is less than the preset value, the discrete points with weak correlation in the third coordinate system are filtered again until the correlation coefficient R 2 is greater than the preset value, and b in the linear relationship at this time is used as the first intercept.

[0118] For example, see Figure 4 , after linear fitting the first X coordinate and the second X coordinate, the linear relationship between them is obtained as y1=0.6836x1+0.602, and the correlation coefficient R 2 When the correlation coefficient R is 0.5699, 2 If it is less than the preset value of 0.8, the discrete points with weak correlation in the third coordinate system need to be filtered again.

[0119] Afterwards, see Figure 5 , the linear relationship between the first X coordinate and the second X coordinate is y1=1.0204x1+0.4776, and the correlation coefficient is R 2 is 0.9537. At this time, due to the correlation coefficient R 2 It is greater than the preset value of 0.8, so a can be approximately regarded as 1, and b can be used as the first intercept.

[0120] In step S320, as an example, a plurality of first coordinates can be obtained by performing multiple detections on the compatible alignment mark through the first lithography device; a plurality of second coordinates can also be obtained by performing multiple detections on the compatible alignment mark through the second lithography device, where multiple means two or more than two, wherein the first coordinate and the second coordinate have a one-to-one correspondence and are equal in number.

[0121] When obtaining the second error according to the first Y coordinate and the second Y coordinate, a fourth coordinate system about the first Y coordinate and the second Y coordinate can be first established. Specifically, the first Y coordinate can be used as the Y axis of the fourth coordinate system, and the second Y coordinate can be used as the X axis of the fourth coordinate system.

[0122] Then, according to the fourth coordinate system, the first coordinate and the second coordinate are filtered. Specifically, the standard deviation method or the box plot method can be used for filtering. First, the discrete points in the fourth coordinate system are found. Then the first Y coordinate and the second Y coordinate corresponding to the discrete points are found. Then the first Y coordinate and the second Y coordinate are filtered out. At the same time, the first X coordinate and the second X coordinate corresponding to the first Y coordinate and the second Y coordinate are also filtered, so as to filter the first coordinate and the second coordinate.

[0123] Finally, the filtered first Y coordinate and the second Y coordinate are linearly fitted to obtain a second intercept, which is the second error. Specifically, the linear fitting of the first Y coordinate and the second Y coordinate includes performing a correlation analysis based on each scattered point in the fourth coordinate system. When the correlation coefficient is greater than a preset value, it can be considered that the first Y coordinate and the second Y coordinate have a high correlation. The preset value can be selected according to actual needs, for example, it can be 0.8.

[0124] As an example, when linear fitting is performed on the first Y coordinate and the second Y coordinate, the linear relationship y2=cx2+d and the correlation coefficient R can be obtained. 2 When the correlation coefficient R 2 When the correlation coefficient R is greater than the preset value, d is directly used as the second intercept. 2 When the correlation coefficient R is less than the preset value, the discrete points with weak correlation in the fourth coordinate system are filtered again until the correlation coefficient R 2 is greater than the preset value, and d in the linear relationship at this time is used as the first intercept.

[0125] For example, see Figure 6 , after linear fitting the first Y coordinate and the second Y coordinate, the linear relationship between them is y2=1.007x2+0.8889, and the correlation coefficient R 2 is 0.9509. 2 It is greater than the preset value of 0.8, so a can be approximately regarded as 1, and b can be used as the second intercept.

[0126] 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.

[0127] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0128] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features of the above-mentioned 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 specification.

[0129] 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 construed as limiting the scope of the patent 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 patent application shall be subject to the attached claims.

Claims

1. A photolithography method, characterized in that: The method comprises: forming a compatible alignment mark on a test wafer, wherein the compatible alignment mark can be recognized in a first lithography apparatus and can also be recognized in a second lithography apparatus, wherein the first lithography apparatus is used to perform a first lithography process, and the second lithography apparatus is used to perform a second lithography process, and the first lithography process and the second lithography process are lithography processes of different types; Probing the compatible alignment mark by the first lithography device to obtain first data, and probing the compatible alignment mark by the second lithography device to obtain second data; Acquire a detection position error between the first photolithography device and the second photolithography device according to the first data and the second data; Performing a first photolithography process on the process wafer by a first photolithography device to form a first alignment mark on the process wafer; The preliminary mark position of the first alignment mark is detected by a second photolithography device, and the alignment mark position is obtained according to the error between the preliminary mark position and the detected position, and a second photolithography process is performed on the process wafer that has undergone the first photolithography process based on the alignment mark position.

2. The photolithography method according to claim 1, characterized in that: One of the first lithography apparatus and the second lithography apparatus is an optical lithography apparatus, and the other is an electron beam lithography apparatus, The compatible alignment marks include: A plurality of periodically arranged first lines, wherein the first lines extend along a first direction; A plurality of periodically arranged second lines, wherein the second lines extend along a second direction and intersect the first lines.

3. The photolithography method according to claim 2, characterized in that: The compatible alignment mark is a centrally symmetrical structure.

4. The photolithography method according to claim 3, characterized in that: The first direction is perpendicular to the second direction, The compatible alignment marks include a line group L1, a line group L2, a line group L3, and a line group L4, wherein the line group L1, the line group L2, the line group L3, and the line group L4 each include the plurality of periodically arranged first lines and the plurality of periodically arranged second lines, The line group L1 is centrally symmetrical with the line group L3, the line group L2 is centrally symmetrical with the line group L4, the line group L1 is axially symmetrical with the line group L2, and the line group L3 is axially symmetrical with the line group L4.

5. The photolithography method according to claim 3, characterized in that: The first direction is not perpendicular to the second direction, The compatible alignment marks include line group L5, line group L6, line group L7, line group L8, line group L9, line group L10, line group L11 and line group L12, The line group L5 is centrally symmetrical with the line group L9, and both include the plurality of periodically arranged first lines and the plurality of periodically arranged second lines. The line group L7 is centrally symmetrical with the line group L11, and both include a plurality of periodically arranged third lines and a plurality of periodically arranged fourth lines, the third lines extend along a third direction, the fourth lines extend along a fourth direction, and the third lines intersect with the fourth lines. The line group L6 is centrally symmetrical with the line group L10, and both include a plurality of periodically arranged second lines and a plurality of periodically arranged third lines, wherein the second lines intersect with the third lines. The line group L8 is centrally symmetrical to the line group L12 , and both include a plurality of periodically arranged first lines and a plurality of periodically arranged fourth lines, wherein the first lines intersect with the fourth lines.

6. The photolithography method according to claim 1, characterized in that: Forming compatible alignment marks on the test wafer includes: A compatible alignment mark groove or a compatible alignment mark strip is formed on the test wafer.

7. The photolithography method according to claim 1, characterized in that: The first data includes a first coordinate, the first coordinate includes a first X coordinate and a first Y coordinate, the second data includes a second coordinate, the second coordinate includes a second X coordinate and a second Y coordinate, Acquiring a detection position error between the first lithography device and the second lithography device according to the first data and the second data includes: Obtain a first error according to the first X-coordinate and the second X-coordinate; A second error is obtained according to the first Y coordinate and the second Y coordinate.

8. The photolithography method according to claim 7, characterized in that: Probing the compatible alignment mark by the first lithography device to obtain first data, and probing the compatible alignment mark by the second lithography device to obtain second data, comprising: Performing multiple detections on the compatible alignment mark by the first photolithography device to obtain multiple first coordinates; Performing multiple detections on the compatible alignment mark by the second photolithography device to obtain multiple second coordinates, where the second coordinates correspond to the first coordinates one by one; Acquiring a first error according to the first X-coordinate and the second X-coordinate includes: Establishing a third coordinate system about the first X coordinate and the second X coordinate; filtering the first coordinate and the second coordinate according to the third coordinate system; A linear fit is performed on the filtered first X-coordinate and the second X-coordinate to obtain a first intercept, where the first intercept is the first error.

9. The photolithography method according to claim 7, characterized in that: Probing the compatible alignment mark by the first lithography device to obtain first data, and probing the compatible alignment mark by the second lithography device to obtain second data, comprising: Performing multiple detections on the compatible alignment mark by the first photolithography device to obtain multiple first coordinates; Performing multiple detections on the compatible alignment mark by the second photolithography device to obtain multiple second coordinates, where the second coordinates correspond to the first coordinates one by one; Acquiring a second error according to the first Y coordinate and the second Y coordinate includes: Establishing a fourth coordinate system about the first Y coordinate and the second Y coordinate; filtering the first coordinate and the second coordinate according to the fourth coordinate system; A linear fit is performed on the filtered first Y coordinate and the second Y coordinate to obtain a second intercept, where the second intercept is the second error.

10. The photolithography method according to claim 1, characterized in that: The first alignment mark is of the same type as the compatible alignment mark.

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