Mask position precision compensation method
By refining the measurement range of the photomask and iteratively updating the standard documents of the lithography machine, the problem of large positional accuracy deviation during the photomask lithography process was solved, enabling precise correction of the photomask after lithography and improving product quality.
Patent Information
- Application Number
- CN202511274483.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-08
- Publication Date
- 2025-11-07
AI Technical Summary
During the photolithography process of photomasks, the quality of photomask products deteriorates due to the machine tolerance between the measuring machine and the photolithography machine and changes in the standard documents for the positional accuracy of the photolithography machine. This is especially true when the effective area is small, resulting in a large deviation in positional accuracy.
By defining the measurement range of the standard plate according to the mask size, a standard file for the positional accuracy of the lithography machine is generated. After lithography, the positional accuracy of the mask is measured to generate a positional accuracy distribution map. Reverse compensation is performed according to the deviation, and the standard file is iteratively updated to correct the positional accuracy.
It enables precise correction of the positional accuracy of photomasks after photolithography, ensuring that the positional accuracy of photomasks with small effective areas meets the preset requirements, thereby improving the quality of photomask products.
Smart Images
Figure CN120909078A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to mask manufacturing, in particular to a mask position accuracy compensation method. BACKGROUND
[0002] In the photolithography process of the mask, a standard file of the position accuracy of the photolithography machine must be generated before the photolithography, which is used to correct the position of the photolithography machine so that the position accuracy measured after the photolithography is more accurate, that is, the deviation of the position accuracy of the photolithography is as small as possible. However, in the actual production process, due to the machine difference between the measuring machine and the photolithography machine, and the degradation of the standard file of the position accuracy of the photolithography machine (that is, as the state of the photolithography machine changes continuously, the standard file gradually loses the effectiveness of correcting the position of the photolithography machine), the measured position accuracy or the change of the fixed position trend or the variation of the local area will cause the decline of the quality of the mask product.
[0003] On the other hand, the standard file of the position accuracy of the photolithography machine covers almost the entire photolithography machine, but the actual mask product is usually small in size, which will bring another problem. Since the standard file is measured based on the measurement range of the standard version, and then integrated according to the measurement results of each point in the X and Y directions, the standard file is attached with parameters such as scale factor Scale and orthogonal factor Ortho, which are calculated based on the measurement range close to the entire photolithography machine. When the effective area of the mask is small, the scale factor Scale and other parameters used by the standard file are not accurate enough, which will cause a large deviation of the position accuracy of the mask. SUMMARY
[0004] (I) Technical problems to be solved
[0005] In view of the above-mentioned defects of the prior art, the present application provides a mask position accuracy compensation method, which can effectively overcome the defect that the position accuracy deviation of the mask with small effective area is large after photolithography.
[0006] (II) Technical solutions
[0007] In order to achieve the above-mentioned purposes, the present application is realized by the following technical solutions:
[0008] A mask position accuracy compensation method, comprising the following steps:
[0009] S1, limiting the measurement range of the standard version according to the size of the mask, and generating a standard file of the position accuracy of the photolithography machine by using the standard version;
[0010] S2, importing the standard file into the photolithography machine, and performing photolithography on the mask on the photolithography machine;
[0011] S3, measuring the position accuracy of the mask on a measuring machine, and generating a corresponding position accuracy distribution map;
[0012] S4, judging the position deviation condition according to the position accuracy distribution map, if the position deviation does not meet the preset requirement, performing reverse compensation on the current standard file according to the position deviation condition to obtain an updated standard file, and returning to S2, otherwise, entering S5;
[0013] S5, taking the current standard file as the optimal standard file corresponding to the mask lithography.
[0014] Preferably, the measuring the position accuracy of the mask on a measuring machine in S3 and generating a corresponding position accuracy distribution map comprises:
[0015] After effectively cleaning the measuring machine and the back of the mask, measuring the position accuracy of the mask on the measuring machine;
[0016] According to the measurement result of the position accuracy of the mask, generating a corresponding position accuracy distribution map.
[0017] Preferably, the judging the position deviation condition according to the position accuracy distribution map in S4, if the position deviation does not meet the preset requirement, performing reverse compensation on the current standard file according to the position deviation condition to obtain an updated standard file, and returning to S2, otherwise, entering S5, comprises:
[0018] According to the position accuracy distribution map, if there is a fixed position deviation or a local area deviation, it is judged that the position deviation does not meet the preset requirement, and the current standard file is compensated in reverse according to the position deviation condition to obtain an updated standard file, and returning to S2;
[0019] If there is no fixed position deviation and no local area deviation, it is judged that the position deviation meets the preset requirement, and S5 is entered.
[0020] Preferably, the performing reverse compensation on the current standard file according to the position deviation condition to obtain an updated standard file comprises:
[0021] Based on the bilinear interpolation principle, the position deviation of each measurement grid of the mask is interpolated to the corresponding position of the current standard file to compensate the current standard file in reverse to obtain an updated standard file.
[0022] (Three) beneficial effects
[0023] Compared with the prior art, the mask position precision compensation method provided by the application firstly limits the measurement range of the standard plate according to the mask size, refines the measurement range of the standard plate, generates a standard file of the position precision of the photolithography machine by using the standard plate, further optimizes the standard file according to the measurement result of the position precision of the mask, and realizes the accurate correction of the position precision of the mask through the iterative upgrade of the standard file, so as to ensure the position precision of the mask after photolithography. BRIEF DESCRIPTION OF DRAWINGS
[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.
[0025] Figure 1 The flowchart of the present application;
[0026] Figure 2 The schematic diagram of the standard file coverage range in the present application;
[0027] Figure 3 The schematic diagram of the measurement range of the standard plate (i.e. the standard file coverage range) limited according to the mask size in the present application;
[0028] Figure 4 The schematic diagram of the position precision distribution map in the present application. DETAILED DESCRIPTION
[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort belong to the protection scope of the present application.
[0030] A mask position precision compensation method, as shown in Figure 1 S1, the measurement range of the standard plate is limited according to the mask size (as shown in Figure 2 and Figure 3 The purpose of this is to refine the measurement range of the standard plate, that is, the standard file coverage range is defined according to the mask size, such as the mask size is 980mm*1150mm, and the measurement range of the standard plate slightly exceeds the mask size range), and a standard file of the position precision of the photolithography machine is generated by using the standard plate.
[0031] S2, importing the standard file into a photolithography machine, and performing photolithography on the mask on a photolithography machine table.
[0032] S3, measuring the position accuracy of the mask on a measuring machine table, and generating a corresponding position accuracy distribution map (as shown in FIG. 2), specifically including: Figure 4
[0033] After effectively cleaning the measuring machine table and the back surface of the mask (to reduce the measurement error of the position accuracy of the mask), measuring the position accuracy of the mask on the measuring machine table;
[0034] According to the measurement result of the position accuracy of the mask, generating a corresponding position accuracy distribution map.
[0035] S4, judging the position deviation condition according to the position accuracy distribution map, if the position deviation does not meet the preset requirement, performing reverse compensation on the current standard file according to the position deviation condition to obtain an updated standard file, and returning to S2, otherwise entering S5, specifically including:
[0036] According to the position deviation condition, if there is a fixed position deviation or a local area deviation, it is judged that the position deviation does not meet the preset requirement, and the current standard file is compensated in reverse to obtain an updated standard file, and returning to S2.
[0037] If there is no fixed position deviation and no local area deviation, it is judged that the position deviation meets the preset requirement, and S5 is entered.
[0038] Specifically, the current standard file is compensated in reverse according to the position deviation condition to obtain an updated standard file, including:
[0039] Based on the principle of bilinear interpolation, the position deviation of each measurement grid of the mask is interpolated to the corresponding position of the current standard file to compensate the current standard file in reverse to obtain an updated standard file.
[0040] S5, taking the current standard file as the optimal standard file corresponding to the photolithography of the mask.
[0041] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A method for mask position accuracy compensation, the method comprising: The method comprises the following steps: S1, limiting the measurement range of a standard mask according to mask size limitation standard, and generating a standard file of lithography machine position accuracy by using the standard mask; S2, importing the standard file into the lithography machine, and performing photolithography on the mask on the lithography machine table; S3, measuring the position accuracy of the mask on the measurement machine table, and generating a corresponding position accuracy distribution map; S4, judging the position deviation according to the position accuracy distribution map, if the position deviation does not meet the preset requirement, performing reverse compensation on the current standard file according to the position deviation to obtain an updated standard file, and returning to S2, otherwise, entering S5; S5, taking the current standard file as the optimal standard file corresponding to the mask photolithography.
2. The mask position accuracy compensation method of claim 1, wherein: In S3, the position accuracy of the mask is measured on the measurement machine table, and a corresponding position accuracy distribution map is generated, comprising: After effectively cleaning the measurement machine table and the back surface of the mask, the position accuracy of the mask is measured on the measurement machine table; According to the measurement result of the position accuracy of the mask, a corresponding position accuracy distribution map is generated.
3. The mask position accuracy compensation method of claim 1, wherein: In S4, the position deviation is judged according to the position accuracy distribution map, if the position deviation does not meet the preset requirement, the current standard file is compensated in reverse according to the position deviation to obtain an updated standard file, and returning to S2, otherwise, entering S5, comprising: According to the position accuracy distribution map, if there is a fixed position deviation or a local area deviation, it is judged that the position deviation does not meet the preset requirement, the current standard file is compensated in reverse according to the position deviation to obtain an updated standard file, and returning to S2; If there is no fixed position deviation and no local area deviation, it is judged that the position deviation meets the preset requirement, and S5 is entered.
4. The mask position accuracy compensation method of claim 3, wherein: The reverse compensation of the current standard file according to the position deviation to obtain an updated standard file comprises: Based on the bilinear interpolation principle, the position deviation of each measurement grid of the mask is interpolated to the corresponding position of the current standard file to compensate the current standard file in reverse to obtain an updated standard file.