Search

CN-121995699-A - Photoetching method and photoetching structure

CN121995699ACN 121995699 ACN121995699 ACN 121995699ACN-121995699-A

Abstract

The disclosure relates to a lithography method and a lithography structure, wherein the lithography method comprises the steps of sequentially forming a first anti-reflection coating, a second anti-reflection coating and a photoresist layer above a substrate, wherein the first anti-reflection coating is a developable anti-reflection coating, patterning the photoresist layer, etching the second anti-reflection coating by using the patterned photoresist layer, patterning the first anti-reflection coating by using a development process, the patterned photoresist layer and the etched second anti-reflection coating, and etching the substrate by using the patterned second anti-reflection layer. The photoetching method utilizes two different types of anti-reflection coatings to elastically adjust the process depth-to-width ratio (ASPECT RATE) and the etching blocking capability, and simultaneously, the development process is adopted in the photoetching method, so that the cost can be reduced.

Inventors

  • HUANG JIANWEI
  • DU JUNHONG
  • Xia deyang
  • WEI YUNONG
  • WU XINDE

Assignees

  • 成都新紫光半导体科技有限公司

Dates

Publication Date
20260508
Application Date
20241104

Claims (10)

  1. 1. A lithographic method, comprising: sequentially forming a first anti-reflection coating, a second anti-reflection coating and a photoresist layer above a substrate, wherein the first anti-reflection coating is a developable anti-reflection coating; patterning the photoresist layer and etching the second anti-reflection coating layer by using the patterned photoresist layer; patterning the first anti-reflective coating using a developing process and the patterned photoresist layer and the etched second anti-reflective coating; And etching the substrate by using the patterned second anti-reflection layer.
  2. 2. The method of claim 1, wherein the developing process and the patterned photoresist layer and the etched second anti-reflective coating layer are used to pattern the first anti-reflective coating layer, and wherein the developer is TMAH.
  3. 3. The lithographic method of claim 1, wherein a thickness of the first anti-reflective coating is greater than a thickness of the second anti-reflective coating.
  4. 4. The method of claim 1, wherein the photoresist layer has a thickness greater than a thickness of the second anti-reflective coating layer.
  5. 5. The method of claim 4, wherein a ratio of thicknesses of the photoresist layer to the second anti-reflective coating layer is 2-12.
  6. 6. The method of claim 1, wherein the second anti-reflective coating layer has a thickness of 250A or greater.
  7. 7. A lithographic structure, comprising: An anti-reflective coating comprising a developable first anti-reflective coating and a second anti-reflective coating disposed over the first anti-reflective coating, and And the photoresist layer is arranged above the second anti-reflection coating.
  8. 8. A lithographic structure according to claim 7, wherein the thickness of the first anti-reflective coating is greater than the thickness of the second anti-reflective coating, and/or The photoresist layer has a thickness greater than a thickness of the second anti-reflective coating layer.
  9. 9. The lithographic structure of claim 8, wherein a ratio of thicknesses of the photoresist layer to the second anti-reflective coating layer is 2-12.
  10. 10. The lithographic structure of claim 7, wherein a thickness of the second anti-reflective coating is 250A or greater.

Description

Photoetching method and photoetching structure Technical Field The present disclosure relates to the field of photolithography, and in particular, to a photolithography method and a photolithography structure. Background In the wafer process, the lithography process is effective to control the reflectivity and resist thickness sufficient to block reactive ion etching, and dry ArF lithography FILM SCHEME is typically pr+barc, and immersion ArF is pr+barc+apf or pr+tri-layer (Si-arc+soc). However, in Bi-LAYER FILM SCHEME (pr+barc), a sufficient photoresist thickness is required, and the CD (critical dimension) cannot be too small and the DoF (depth of field) cannot be too large due to aspect ratio problems. In the immersion ArF, there can be better CD (critical dimension) and DoF (depth of field), but the BARC+APF or Si-ARC+SOC needs etching, and the cost is higher. Disclosure of Invention The purpose of the disclosure is to provide a lithography method and a lithography structure, wherein the lithography method can elastically adjust the process depth-to-width ratio (ASPECT RATE) and the etching blocking capability by using two different types of anti-reflection coatings, and meanwhile, the development process is adopted in the lithography method, so that the cost can be reduced. To achieve the above object, according to a first aspect of the present disclosure, there is provided a lithographic method comprising: sequentially forming a first anti-reflection coating, a second anti-reflection coating and a photoresist layer above a substrate, wherein the first anti-reflection coating is a developable anti-reflection coating; patterning the photoresist layer and etching the second anti-reflection coating layer by using the patterned photoresist layer; patterning the first anti-reflective coating using a developing process and the patterned photoresist layer and the etched second anti-reflective coating; And etching the substrate by using the patterned second anti-reflection layer. Optionally, the developing process and the patterned photoresist layer and the etched second anti-reflection coating are used for patterning the first anti-reflection coating, and the developing agent adopts TMAH. Optionally, the thickness of the first anti-reflective coating is greater than the thickness of the second anti-reflective coating. Optionally, the photoresist layer has a thickness greater than a thickness of the second anti-reflective coating layer. Optionally, the ratio of the thickness of the photoresist layer to the thickness of the second anti-reflection coating layer is 2-12. Optionally, the thickness of the second anti-reflection coating is greater than or equal to 250A. According to a second aspect of the present disclosure, there is also provided a lithographic structure comprising: An anti-reflective coating comprising a developable first anti-reflective coating and a second anti-reflective coating disposed over the first anti-reflective coating, and And the photoresist layer is arranged above the second anti-reflection coating. Optionally, the thickness of the first anti-reflective coating layer is greater than the thickness of the second anti-reflective coating layer, and/or The photoresist layer has a thickness greater than a thickness of the second anti-reflective coating layer. Optionally, the ratio of the thickness of the photoresist layer to the thickness of the second anti-reflection coating layer is 2-12. Optionally, the thickness of the second anti-reflection coating is greater than or equal to 250A. According to the technical scheme, the photoetching method sequentially forms the first anti-reflection coating, the second anti-reflection coating and the photoresist layer on the substrate, and as the first anti-reflection coating is the developable anti-reflection coating, the photoresist layer is firstly opened through patterning, then the second anti-reflection coating is opened through etching, then the first anti-reflection coating is opened through the patterned photoresist layer and the opened second anti-reflection coating through a developing process, and finally a required structure is formed on the substrate through a common etching process. The photolithography method of the present disclosure provides a new mask solution that can meet the reflectivity control by adjusting the thickness of the first and second anti-reflective coatings, e.g., the thickness of the first anti-reflective coating can be thicker and the thickness of the second anti-reflective coating can be thinner. In addition, the photoetching method comprises exposure, development, etching, development and etching of a substrate, and compared with the related technology, the method adopts two development and one intermediate etching processes, on one hand, the process depth-to-width ratio (ASPECT RATE) and etching blocking capability can be elastically adjusted by utilizing two different types of anti-reflection coatings, and on t