Photomask HTM repairing method based on light spot moving speed

Abstract

The invention relates to photomask HTM repairing, in particular to a photomask HTM repairing method based on the light spot moving speed, and the method comprises the steps: measuring the linear relation between the film thickness and the transmittance of different substrates according to the basic relation between the film thickness and the transmittance; moving the coating equipment to a to-be-repaired area of the photomask HTM, and measuring the transmittance of a non-repaired area; according to the linear relation between the film thickness and the transmittance of different substrates, the initial light spot moving speed and the coating frequency are obtained, and coating process parameters are set; coating equipment is used for coating and repairing the to-be-repaired area of the photomask HTM, and the light spot moving speed is adjusted during each time of coating and repairing; after the corresponding coating times are reached and coating repair work is completed, the transmittance of the to-be-repaired area is measured and compared with the transmittance of the non-repaired area; according to the technical scheme provided by the invention, the defects that the uniformity of the repaired area is poor and the transmittance is difficult to accurately control in the prior art can be effectively overcome.

Description

Technical Field

[0001] The present invention relates to a photomask HTM repair, and in particular to a photomask HTM repair method based on light spot moving speed. Background Art

[0002] Currently, HTM (Hard Tone Mask) is a key product among photomask products, widely used in PS layers in the TFT-CF industry, the TFT-array industry, and even in the high-end OLED industry. However, repairing HTM photomasks has always been a technical challenge, requiring extremely high uniformity in the repaired area and accurate transmittance of the semi-transparent layer.

[0003] The main problems with traditional CVD technology applied to photomask HTM repair are as follows:

[0004] 1) Poor uniformity: When repairing the HTM photomask in a single pass, the thickness of the chromium gas deposition is uneven, resulting in poor uniformity in the repaired area;

[0005] 2) Low efficiency: It takes a while for the gas to stabilize before repairing (such as chromium gas needs about 15 minutes), and the light spot moves slowly, resulting in a long repair time and affecting production efficiency;

[0006] 3) Difficulty in operation control: Due to the one-time film formation, the transmittance control accuracy of the photomask HTM is low. Summary of the Invention

[0007] (1) Technical problems solved

[0008] In response to the above-mentioned shortcomings of the prior art, the present invention provides a photomask HTM repair method based on the light spot moving speed, which can effectively overcome the defects of the prior art such as poor uniformity of the repair area and difficulty in accurately controlling the transmittance.

[0009] (2) Technical solution

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0011] The photomask HTM repair method based on the light spot moving speed includes the following steps:

[0012] S1. Based on the basic relationship between film thickness and transmittance, measure the linear relationship between film thickness and transmittance of different substrates;

[0013] S2. Move the coating equipment to the area to be repaired of the photomask HTM and measure the transmittance of the non-repaired area;

[0014] S3. According to the linear relationship between the film thickness and transmittance of different substrates, the initial light spot moving speed and the number of coating times are obtained, and the coating process parameters are set;

[0015] S4, using a coating device to perform coating repair on the area to be repaired of the photomask HTM, and adjusting the moving speed of the light spot during each coating repair;

[0016] S5. After the coating repair work is completed after the corresponding coating times, the transmittance of the area to be repaired is measured and compared with the transmittance of the non-repaired area.

[0017] Preferably, in S1, based on the basic relationship between film thickness and transmittance, the linear relationship between film thickness and transmittance of different substrates is measured, including:

[0018] S11. Determine the basic relationship between film thickness and transmittance:

[0019]

[0020] Where T is the transmittance, T0 is the initial transmittance, that is, the transmittance of the substrate itself, α is the absorption coefficient of the coating material, and d is the film thickness;

[0021] S12. Based on the basic relationship between film thickness and transmittance, measure the linear relationship between film thickness and transmittance of different substrates.

[0022] Preferably, in S3, the initial light spot moving speed and the number of coating times are obtained according to the linear relationship between the film thickness and transmittance of different substrates, and the coating process parameters are set, including:

[0023] S31, taking the transmittance of the non-repaired area of ​​the photomask HTM as the target transmittance;

[0024] S32, determining a target film thickness of the substrate based on a linear relationship between film thickness and transmittance of different substrates;

[0025] S33, determining the initial light spot moving speed and the number of coating times according to the target film thickness of the substrate;

[0026] S34, setting coating process parameters.

[0027] Preferably, the coating process parameters include spot size and alignment accuracy.

[0028] Preferably, in S4, coating and repairing the to-be-repaired area of ​​the photomask HTM by using a coating device, and adjusting the moving speed of the light spot during each coating and repairing, including:

[0029] S41, using a coating device to perform coating repair on the to-be-repaired area of ​​the photomask HTM, and measuring the transmittance of the to-be-repaired area after each coating repair;

[0030] S42, comparing the transmittance of the area to be repaired with the target transmittance, and adjusting the moving speed of the light spot for the next coating repair according to the comparison result;

[0031] Among them, the coating repair is carried out by using a chromium gas uniform deposition method.

[0032] Preferably, in S42, the transmittance of the area to be repaired is compared with the target transmittance, and the moving speed of the light spot for the next coating repair is adjusted according to the comparison result, including:

[0033] The transmittance of the area to be repaired is compared with the target transmittance. By increasing the speed of the light spot movement, the film thickness of a single coating repair is reduced and the uniformity of the deposition is improved; by reducing the speed of the light spot movement, the film thickness of a single coating repair is increased.

[0034] (3) Beneficial effects

[0035] Compared with the existing technology, the photomask HTM repair method based on the light spot movement speed provided by the present invention achieves uniform deposition of chromium gas during the photomask HTM repair process by adjusting the CVD light spot movement speed and combining multiple coating repair methods, effectively improving the repair efficiency and being able to accurately control the transmittance, and well solving the problems of long repair time, poor uniformity of the repair area, and low transmittance control accuracy under traditional repair methods, thereby significantly improving the photomask HTM repair level. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0037] Figure 1 It is a schematic diagram of the process of the present invention;

[0038] Figure 2 Schematic diagram of performing multiple coating repairs on the area to be repaired of the photomask HTM in the present invention;

[0039] Figure 3 This is a diagram showing the effect of performing multiple coating repairs on the area to be repaired of the photomask HTM in the present invention;

[0040] Figure 4 Schematic diagram of the linear relationship between the film thickness and transmittance of the PS layer measured in the TFT-CF industry in the present invention;

[0041] Figure 5 This is a schematic diagram of the linear relationship between film thickness and transmittance measured in the OLED-AM industry in the present invention. DETAILED DESCRIPTION

[0042] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0043] The photomask HTM repair method based on the light spot moving speed, such as Figure 1 As shown, S1, based on the basic relationship between film thickness and transmittance, the linear relationship between film thickness and transmittance of different substrates is measured, specifically including:

[0044] S11. Determine the basic relationship between film thickness and transmittance:

[0045] T=T0e -αd ;

[0046] Where T is the transmittance, T0 is the initial transmittance, that is, the transmittance of the substrate itself, α is the absorption coefficient of the coating material, and d is the film thickness;

[0047] S12. Based on the basic relationship between film thickness and transmittance, the linear relationship between film thickness and transmittance of different substrates was measured (e.g. Figure 4 and Figure 5 shown).

[0048] Based on the basic relationship between film thickness and transmittance, the above technical solution shows that there are two main factors affecting transmittance: substrate material and film thickness. To find the linear relationship between film thickness and transmittance for different substrates, a comparative test was conducted on three common mask suppliers. The results are shown in Table 1:

[0049] Table 1 Relationship between film thickness and transmittance of different substrates

[0050]

[0051] In addition, for the linear relationship between the film thickness and transmittance of the PS layer in the TFT-CF industry and the substrate in the OLED-AM industry, the measurement results are as follows: Figure 4 、 Figure 5 shown.

[0052] S2. Move the coating device to the area to be repaired of the photomask HTM, and measure the transmittance of the non-repaired area.

[0053] S3. Based on the linear relationship between the film thickness and transmittance of different substrates, the initial light spot moving speed and the number of coating times are obtained, and the coating process parameters are set, including:

[0054] S31, taking the transmittance of the non-repaired area of ​​the photomask HTM as the target transmittance;

[0055] S32, determining a target film thickness of the substrate based on a linear relationship between film thickness and transmittance of different substrates;

[0056] S33, determining the initial light spot moving speed and the number of coating times according to the target film thickness of the substrate;

[0057] S34. Set coating process parameters (including spot size and alignment accuracy).

[0058] S4. Using a coating device to perform coating repair on the area to be repaired of the photomask HTM, and adjusting the moving speed of the light spot during each coating repair, specifically including:

[0059] S41, using a coating device to perform coating repair on the to-be-repaired area of ​​the photomask HTM, and measuring the transmittance of the to-be-repaired area after each coating repair;

[0060] S42, comparing the transmittance of the area to be repaired with the target transmittance, and adjusting the moving speed of the light spot for the next coating repair according to the comparison result;

[0061] Among them, the coating repair is carried out by using a chromium gas uniform deposition method.

[0062] Specifically, in S42, the transmittance of the area to be repaired is compared with the target transmittance, and the moving speed of the light spot for the next coating repair is adjusted according to the comparison result, including:

[0063] The transmittance of the area to be repaired is compared with the target transmittance. By increasing the speed of the light spot movement, the film thickness of a single coating repair is reduced and the uniformity of the deposition is improved; by reducing the speed of the light spot movement, the film thickness of a single coating repair is increased.

[0064] S5. After the coating repair work is completed after the corresponding coating times, the transmittance of the area to be repaired is measured and compared with the transmittance of the non-repaired area.

[0065] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A photomask HTM repair method based on light spot moving speed, characterized by: The following steps are involved: S1. Based on the basic relationship between film thickness and transmittance, measure the linear relationship between film thickness and transmittance of different substrates; S2. Move the coating equipment to the area to be repaired of the photomask HTM and measure the transmittance of the non-repaired area; S3. According to the linear relationship between the film thickness and transmittance of different substrates, the initial light spot moving speed and the number of coating times are obtained, and the coating process parameters are set; S4, using a coating device to perform coating repair on the area to be repaired of the photomask HTM, and adjusting the moving speed of the light spot during each coating repair; S5. After the coating repair work is completed after the corresponding coating times, the transmittance of the area to be repaired is measured and compared with the transmittance of the non-repaired area.

2. The photomask HTM repair method based on light spot moving speed according to claim 1, characterized in that: In S1, based on the basic relationship between film thickness and transmittance, the linear relationship between film thickness and transmittance of different substrates is measured, including: S11. Determine the basic relationship between film thickness and transmittance: T=T0e -αd ; Where T is the transmittance, T0 is the initial transmittance, that is, the transmittance of the substrate itself, α is the absorption coefficient of the coating material, and d is the film thickness; S12. Based on the basic relationship between film thickness and transmittance, measure the linear relationship between film thickness and transmittance of different substrates.

3. The photomask HTM repair method based on light spot moving speed according to claim 2, characterized in that: In S3, the initial spot movement speed and coating times are obtained based on the linear relationship between the film thickness and transmittance of different substrates, and the coating process parameters are set, including: S31, taking the transmittance of the non-repaired area of ​​the photomask HTM as the target transmittance; S32, determining a target film thickness of the substrate based on a linear relationship between film thickness and transmittance of different substrates; S33, determining the initial light spot moving speed and the number of coating times according to the target film thickness of the substrate; S34, setting coating process parameters.

4. The photomask HTM repair method based on light spot moving speed according to claim 3, characterized in that: The coating process parameters include spot size and alignment accuracy.

5. The photomask HTM repair method based on light spot moving speed according to claim 3, characterized in that: In S4, the coating equipment is used to coat and repair the area to be repaired of the photomask HTM, and the moving speed of the light spot is adjusted during each coating repair, including: S41, using a coating device to perform coating repair on the to-be-repaired area of ​​the photomask HTM, and measuring the transmittance of the to-be-repaired area after each coating repair; S42, comparing the transmittance of the area to be repaired with the target transmittance, and adjusting the moving speed of the light spot for the next coating repair according to the comparison result; Among them, the coating repair is carried out by using a chromium gas uniform deposition method.

6. The photomask HTM repair method based on light spot moving speed according to claim 5, characterized in that: In S42, the transmittance of the area to be repaired is compared with the target transmittance, and the moving speed of the light spot for the next coating repair is adjusted according to the comparison result, including: The transmittance of the area to be repaired is compared with the target transmittance. By increasing the speed of the light spot movement, the film thickness of a single coating repair is reduced and the uniformity of the deposition is improved; by reducing the speed of the light spot movement, the film thickness of a single coating repair is increased.

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