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CN-121995560-A - Method for forming binary grating structure by one-time etching

CN121995560ACN 121995560 ACN121995560 ACN 121995560ACN-121995560-A

Abstract

The invention provides a method for forming a binary grating structure by one-time etching, which comprises the steps of providing a substrate, forming a grating film layer on the surface of the substrate, forming a mask layer on the surface of the grating film layer, patterning the mask layer, and forming a second grating structure on the second grating region, wherein the mask layer is formed on the surface of the grating film layer, the shape of the mask layer on the first grating region is different from that of the mask layer on the second grating region, the patterned mask layer is used as a mask, the first grating structure is formed on the first grating region, the second grating structure is formed on the second grating region, and the shape of the first grating structure is different from that of the second grating structure. The method realizes one-time etching of the binary grating, forms various grating structures through one-time etching, and improves the production efficiency and the performance of the optical waveguide product.

Inventors

  • CHEN DINGQIANG
  • CHEN HEFENG
  • GUO XUHONG
  • PU HUI
  • LI KUNPENG
  • LOU XINYE

Assignees

  • 上海鲲游科技有限公司

Dates

Publication Date
20260508
Application Date
20240329

Claims (10)

  1. 1. A method of forming a binary grating structure by one etching, comprising: the method comprises the steps of providing a substrate, wherein the substrate comprises a first grating region and a second grating region which are sequentially arranged, forming a grating film layer on the surface of the substrate, and the thickness of the grating film layer on the first grating region is larger than that of the grating film layer on the second grating region; Forming a mask layer on the surface of the grating film layer, and patterning the mask layer, wherein the shape of the mask layer on the first grating region is different from that of the mask layer on the second grating region; and taking the patterned mask layer as a mask, etching the grating film layer once, forming a first grating structure on the first grating region, forming a second grating structure on the second grating region, forming the binary grating structure, and enabling the morphology of the first grating structure to be different from that of the second grating structure.
  2. 2. The method of claim 1, wherein the mask layer on the first grating region is flush with the surface of the mask layer on the first grating region, and wherein the grating layer is etched once to form blazed, trapezoid shaped or skewed gratings in the region where the higher grating layer is formed and straight gratings in the region where the lower grating layer is formed.
  3. 3. The method of forming a binary grating structure by one etching according to claim 2, wherein, The difference between the thickness of the grating film layer formed on the first grating region and the thickness of the surface of the grating film layer formed on the second grating region is a first difference value △H=(h 1 -h 2 )*S; Wherein H 1 is the height of the first grating structure, H 2 is the height of the second grating structure, S is the etching selection ratio of the patterned mask layer to the grating film layer, and DeltaH is the first difference; S=V Mask layer /V Grating film layer ; Where V Mask layer is the etch rate of the patterned mask layer and V Grating film layer is the etch rate of the grating film layer.
  4. 4. A method of forming a binary grating structure by one etch according to claim 3, The etching time of one etching of the grating film layer is the first etching time T=h 2 /V Grating film layer +△H/V Mask layer ; Wherein T is the first etching time.
  5. 5. The method of forming a binary grating structure by one etching of claim 4, wherein, The first grating structure height H 1 and the thickness H 1 of the mask layer on the first grating region, the second grating structure height H 2 and the thickness H 2 of the mask layer on the second grating region respectively satisfy the following relations: thickness H 1 of the mask layer on the first grating region: H 1 =h 1 *S; Thickness H 2 of the mask layer on the second grating region: H 2 >h 2 *S。
  6. 6. the method of forming a binary grating structure by one etching according to claim 1, wherein the method of forming a grating film layer on the surface of the substrate comprises: Forming a first grating film on a surface of the substrate; forming a first patterned photoresist layer on the surface of the first grating film in the second grating region; Plating a layer of second grating film with a first thickness on the surface of the first patterned photoresist layer and the surface of the first grating film of the first grating area; And removing the first patterned photoresist layer.
  7. 7. The method of forming a binary grating structure by one etching according to claim 1, wherein the method of forming a grating film layer on the surface of the substrate comprises: Forming a first grating film on a surface of the substrate; forming a second patterned photoresist layer on the surface of the first grating film of the first grating region; Etching the first grating film with the first thickness and located in the second grating area by taking the second patterned photoresist layer as a mask; And removing the second patterned photoresist layer.
  8. 8. The method of forming a binary grating structure by one etching according to claim 1 or 2, wherein the substrate further comprises a third grating region, and when forming a first grating structure on the first grating region and a second grating structure on the second grating region, further comprising: And forming a third grating structure in the third grating region, wherein the height of the third grating structure is different from that of the second grating structure.
  9. 9. The method of claim 8, wherein a difference between a thickness of the grating layer formed on the first grating region and a thickness of a surface of the grating layer formed on the second grating region or the third grating region is a first difference △H=(h 1 -max(h 2 ,h 3 ))*S; Wherein H 1 is the height of the first grating structure, H 2 is the height of the second grating structure, S is the etching selection ratio of the patterned mask layer to the grating film layer, H 3 is the height of the third grating structure, and ΔH is the first difference.
  10. 10. The method of claim 8 or 9, wherein the etching time for etching the grating layer at one time is a first etching time, and the first etching time t=max (h 2 ,h 3 ）/V Grating film layer +△H/V Mask layer ; wherein T is the first etching time.

Description

Method for forming binary grating structure by one-time etching The scheme is a divisional application, the application number of the original application is 2024103817893, and the application date is 2024.03.29. Technical Field The invention relates to the field of semiconductor devices, in particular to a method for forming a binary grating structure by one-time etching. Background Compared with the unitary grating, the optical waveguide manufactured based on the binary grating has higher efficiency, so that under the condition of not increasing the complexity of the procedure, developing a single embossing and etching binary grating has remarkable significance, the overall performance of the product is directly improved, and the cost of the product is indirectly reduced. In the traditional preparation process, only a single unitary straight tooth structure can be manufactured by single embossing and etching, but binary structure manufacturing cannot be realized, and the manufacturing of the binary structure is realized by adopting the technological means such as multiple embossing and etching. However, the process efficiency of multiple imprinting is low, the cost is high, the stability and consistency of the manufacturing structure are difficult to ensure, the performance of the grating structure product is poor, and the mass production is not facilitated. Therefore, how to prepare the binary grating structure by a single imprint process is a technical problem that needs to be solved by those skilled in the art. Disclosure of Invention The invention provides a method for forming a binary grating structure by one-time etching, which solves the problem of how to form the binary grating structure by one-time etching, and forms the required binary grating structure by one-time etching. According to a first aspect of the present invention, there is provided a method for forming a binary grating structure by one etching, comprising: Providing a substrate, wherein the substrate comprises a first grating region and a second grating region which are sequentially arranged; forming a grating film layer on the surface of the substrate, wherein the thickness of the grating film layer on the first grating region is larger than that of the grating film layer on the second grating region; Forming a mask layer on the surface of the grating film layer, and patterning the mask layer, wherein the shape of the mask layer on the first grating region is different from that of the mask layer on the second grating region; and taking the patterned mask layer as a mask, etching the grating film layer once, forming a first grating structure on the first grating region, forming a second grating structure on the second grating region, forming the binary grating structure, and enabling the morphology of the first grating structure to be different from that of the second grating structure. Optionally, the mask layer located in the first grating region is flush with the surface of the mask layer located on the first grating region. Optionally, a difference between the thickness of the grating film layer formed on the first grating region and the thickness of the surface of the grating film layer formed on the second grating region is a first difference △H=(h1-h2)*S; Wherein H 1 is the height of the first grating structure, H 2 is the height of the second grating structure, S is the etching selection ratio of the patterned mask layer to the grating film layer, and DeltaH is the first difference; S=V Mask layer /V Grating film layer ; Where V Mask layer is the etch rate of the patterned mask layer and V Grating film layer is the etch rate of the grating film layer. Optionally, the etching time of one etching of the grating film layer is a first etching time T=h2/V Grating film layer +△H/V Mask layer ; Wherein T is the first etching time. Optionally, the first grating structure height H 1 and the thickness H 1 of the mask layer on the first grating region, and the second grating structure height H 2 and the thickness H 2 of the mask layer on the second grating region respectively satisfy the following relations: thickness H 1 of the mask layer on the first grating region: H1=h1*S; Thickness H 2 of the mask layer on the second grating region: H2>h2*S。 Optionally, forming a mask layer on the surface of the grating film layer and patterning the mask layer, specifically, forming a first patterned mask layer on the surface of the grating film layer on the first grating region and forming a second patterned mask layer on the surface of the grating film layer on the second grating region, and further defining as Forming a mask material layer on the surface of the grating film layer, wherein the mask material layer in the first grating region is flush with the mask material layer in the second grating region in height; and carrying out patterning treatment on the mask material layer to form the first patterned mask layer on the surface of the