CN-122018226-A - Photomask processing method

CN122018226ACN 122018226 ACN122018226 ACN 122018226ACN-122018226-A

Abstract

The application provides a photomask processing method, and relates to the technical field of photomasks. The method comprises the steps of forming a first etching barrier layer, forming a first etching pattern on the first etching barrier layer, etching a phase shift layer and a shading layer of a product to be processed, transferring the first etching pattern to the phase shift layer and the shading layer, removing the first etching barrier layer, forming a second etching barrier layer on the surface of the product to be processed, forming a second etching pattern and a third etching pattern on the second etching barrier layer, combining the third etching pattern and the first etching pattern to form an etching pattern to be processed, etching the shading layer, transferring the second etching pattern and the third etching pattern to the shading layer, removing the second etching barrier layer, providing an etching barrier frame, exposing at least the area corresponding to the third etching pattern by the etching barrier frame, and removing the etching barrier frame after etching the phase shift layer exposed by the etching barrier frame. The method can enhance the integrity of the pattern and reduce the potential risk brought by rotating the pattern.

Inventors

XIAN XIAOZHAI
WANG ZHAOHUI
JIA RUIBIN
LI GEN

Assignees

泉意光罩光电科技(济南)有限公司

Dates

Publication Date: 20260512
Application Date: 20260324

Claims (10)

1. A method of processing a photomask, comprising: Forming a first etching barrier layer on the surface of a product to be processed, wherein the product to be processed comprises a substrate layer, a phase shift layer and a shading layer, wherein the phase shift layer and the shading layer are arranged on the substrate layer in a stacked mode, the first etching barrier layer covers the shading layer, and a first etching pattern is formed on the first etching barrier layer; etching the phase shift layer and the light shielding layer to transfer the first etched pattern onto the phase shift layer and the light shielding layer; Removing the first etching barrier layer, and forming a second etching barrier layer on the surface of the product to be processed, wherein the second etching barrier layer is provided with a second etching pattern and a third etching pattern, and the third etching pattern and the first etching pattern are combined to form an etching pattern to be processed; etching the light shielding layer to transfer the second etching pattern and the third etching pattern onto the light shielding layer; Removing the second etching barrier layer; Providing an etching barrier frame and placing the etching barrier frame above the product to be processed, wherein the etching barrier frame at least exposes a region corresponding to the third etching pattern; and removing the etching barrier frame after etching the phase shift layer exposed by the etching barrier frame.
2. The method of claim 1, wherein forming a first etch stop layer on a surface of a product to be processed comprises: Forming a first photoresist layer on the surface of the product to be processed, inputting a first etching pattern into a first exposure machine, and exposing the first photoresist layer by adopting the first exposure machine; and developing the exposed first photoresist layer to form a first etching barrier layer.
3. The method of claim 2, wherein the first exposure tool is an EBM tool, and the third etching pattern is the same as a pattern to be processed in a shielding region of the EBM tool with respect to the product to be processed.
4. The method of claim 1, wherein the method further comprises, prior to forming the first etch stop layer on the surface of the product to be processed: Determining an etching pattern to be processed; Before forming the second etching barrier layer on the surface of the product to be processed, the method further comprises: and recording the pattern difference between the first etching pattern and the etching pattern, and recording the pattern difference as a third etching pattern.
5. The method of claim 4, wherein forming a second etch stop layer on a surface of the product to be processed comprises: forming a second photoresist layer on the surface of the product to be processed, inputting the second etching pattern and the third etching pattern into a second exposure machine, and exposing the second photoresist layer by adopting the second exposure machine; and developing the exposed second photoresist layer to form a second etching barrier layer.
6. The method of claim 4, wherein the pattern difference between the first etched pattern and the etched pattern is recorded using EDA software.
7. The method of claim 5, wherein the second exposure tool is a laser exposure tool.
8. The method of claim 1, wherein the etch stop frame is provided with a first alignment mark, and the first alignment mark is used for aligning the etch stop frame with the product to be processed.
9. The method of claim 1, wherein the etching the phase shift layer and the light shielding layer comprises: etching the phase shift layer and the light shielding layer by using plasma; etching the phase shift layer exposed by the etch stop frame includes: And etching the phase shift layer exposed by the etching barrier frame by plasma.
10. The method of claim 1, wherein the substrate layer is a quartz layer, the phase shift layer is a Mo/Si multilayer film, and the light shielding layer is a chromium layer.

Description

Photomask processing method Technical Field The application relates to the technical field of photomask processing, in particular to a photomask processing method. Background The manufacture of high-order PSM photomasks usually adopts an EBM machine to complete the exposure process, the machine is provided with a grounding needle, and the core function of the machine is to release charges accumulated by electron beams in the working process of the machine, so that the process stability is ensured. However, the grounding pin is arranged at the edge of the photomask, so that physical shielding can be formed on the light of the exposure device, the photomask pattern of the corresponding area of the grounding pin cannot be normally exposed, and finally the problem of pattern missing occurs. To solve this problem, the prior art adopts a solution that the whole pattern of the photomask is rotated by a specific angle to avoid the shielding area of the grounding pin. The scheme has the defects that firstly, the scheme needs to be cooperatively matched by multiple departments, fine working treatment and subsequent procedure handover are required to be completed in the process, the operation flow is harsh, the artificial operation risk is easy to generate, secondly, the pattern designs of different photomasks are different, the situation that a grounding needle cannot be avoided after rotation exists, thirdly, the physical shielding problem of the grounding needle is not fundamentally solved, the effective exposure of the corresponding position is always unavailable, the exposure integrity of the photomasks is damaged, and the product acceptance inspection qualification rate is directly influenced. Disclosure of Invention The present application aims to overcome the above-mentioned drawbacks of the prior art, and to provide a method for processing a photomask, which can enhance the integrity of a pattern and reduce the potential risk caused by rotating the pattern. In order to achieve the above purpose, the technical scheme adopted by the embodiment of the application is as follows: The embodiment of the application provides a photomask processing method, which comprises the steps of forming a first etching barrier layer on the surface of a product to be processed, wherein the product to be processed comprises a substrate layer, a phase shift layer and a shading layer which are arranged on the substrate layer in a laminated mode, the first etching barrier layer covers the shading layer, a first etching pattern is arranged on the first etching barrier layer, the phase shift layer and the shading layer are etched to transfer the first etching pattern to the phase shift layer and the shading layer, the first etching barrier layer is removed, a second etching barrier layer is formed on the surface of the product to be processed, a second etching pattern and a third etching pattern are arranged on the second etching barrier layer, the third etching pattern and the first etching pattern are combined to form an etching pattern to be processed, the shading layer is etched to transfer the second etching pattern to the shading layer, the second etching barrier layer is removed, an etching barrier frame is provided and is placed above the product to be processed, at least the area corresponding to the third etching pattern is exposed, and the etching barrier frame is removed after the phase shift layer exposed by the etching barrier frame. Optionally, forming the first etching barrier layer on the surface of the product to be processed comprises forming a first photoresist layer on the surface of the product to be processed, inputting the first etching pattern into a first exposure machine, exposing the first photoresist layer by using the first exposure machine, and developing the exposed first photoresist layer to form the first etching barrier layer. Optionally, the first exposure machine is an EBM machine, and the third etching pattern is the same as a pattern to be processed in a shielding area of the EBM machine, which is grounded to the product to be processed. Optionally, before forming the first etching barrier layer on the surface of the product to be processed, the method further comprises determining an etching pattern to be processed, and before forming the second etching barrier layer on the surface of the product to be processed, the method further comprises recording the pattern difference between the first etching pattern and the etching pattern as a third etching pattern. Optionally, forming a second etching barrier layer on the surface of the product to be processed comprises forming a second photoresist layer on the surface of the product to be processed, inputting the second etching pattern and the third etching pattern into a second exposure machine, exposing the second photoresist layer by using the second exposure machine, and developing the exposed second photoresist layer to form the second etching bar