# US 12,181,794 B2 · Photolithography method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,794 B2 - Document ID: US12181794B2 - Status: Granted - Kind: B2 - Application number: 18/575,719 - Filed: 2022-11-14 - Published: 2024-08-08 - Granted: 2024-12-31 - Earliest claimed: 2021-12-16 - Assignees: The Institute of Optics and Electronics, The Chinese Academy of Sciences - Applicants: The Institute of Optics and Electronics, the Chinese Academy of Sciences - Inventors: Xiangang Luo; Kaipeng Liu; Yunfei Luo; Shuai Mou; Ping Gao; Zeyu Zhao - Web page: https://patentgrep.com/patent/US12181794B2 ## CPC - G03F 1/80: Etching - G03F 1/60: Substrates - G03F 1/82: Auxiliary processes, e.g. cleaning or inspecting - G03F 7/2008: {characterised by the reflectors, diffusers, light or heat filtering means or anti-reflective means used} - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) ## Abstract A photolithography method includes: sequentially preparing a functional film layer, a reflective auxiliary imaging film layer and a first photoresist layer which are stacked, on a photolithography substrate; performing photolithography on the first photoresist layer to obtain a first photolithography structure; etching the reflective auxiliary imaging film layer with the first photolithography structure as a masking layer; on the pattern of the reflective auxiliary imaging film layer, sequentially preparing a second photoresist layer and a transmissive auxiliary imaging film layer which stacked; performing surface plasmon photolithography with the pattern of the reflective auxiliary imaging film layer as a mask, removing the transmissive auxiliary imaging film layer, and then developing the second photoresist layer, to obtain a second photolithography structure; and etching the functional film layer, with the second photolithography structure as a masking layer, to obtain a third photolithography structure. ## Claims ### Claim 1 A photolithography method, comprising: sequentially preparing, on a surface of a photolithography substrate, a functional film layer, a reflective auxiliary imaging film layer and a first photoresist layer which are stacked; performing photolithography on the first photoresist layer to obtain a first photolithography structure; etching the reflective auxiliary imaging film layer with the first photolithography structure as a masking layer, to transfer a pattern of the first photolithography structure to the reflective auxiliary imaging film layer; sequentially preparing, on the pattern of the reflective auxiliary imaging film layer, a second photoresist layer and a transmissive auxiliary imaging film layer which are stacked; performing surface plasmon photolithography with the pattern of the reflective auxiliary imaging film layer as a mask, removing the transmissive auxiliary imaging film layer and developing the second photoresist layer to obtain a second photolithography structure, wherein the surface plasmon photolithography is controlled by a cavity between the transmissive auxiliary imaging film layer and the patterned reflective auxiliary imaging film layer; and etching the functional film layer with the second photolithography structure as a masking layer, to transfer a pattern of the second photolithography structure to the functional film layer to obtain a third photolithography structure. ### Claim 2 (depends on 1) The photolithography method according to claim 1, wherein the reflective auxiliary imaging film layer and the transmissive auxiliary imaging film layer are prepared by using gold, silver, aluminum, or a material with a negative dielectric constant. ### Claim 3 (depends on 2) The photolithography method according to claim 2, wherein the reflective auxiliary imaging film layer and the transmissive auxiliary imaging film layer are prepared by sputtering deposition, evaporation deposition, atomic layer deposition or chemical vapor deposition. ### Claim 4 (depends on 1) The photolithography method according to claim 1, wherein the reflective auxiliary imaging film layer and the transmissive auxiliary imaging film layer are prepared by sputtering deposition, evaporation deposition, atomic layer deposition or chemical vapor deposition. ### Claim 5 (depends on 1) The photolithography method according to claim 1, wherein the first photolithography structure is a periodic structure or an aperiodic structure, and the first photolithography structure has a one-dimensional pattern or a two-dimensional pattern. ### Claim 6 (depends on 1) The photolithography method according to claim 1, wherein the first photoresist layer is subjected to photolithography by surface plasmon photolithography, projection photolithography or electron beam direct writing photolithography. ### Claim 7 (depends on 1) The photolithography method according to claim 1, wherein the reflective auxiliary imaging film layer is etched by ion beam etching or reactive ion etching. ### Claim 8 (depends on 1) The photolithography method according to claim 1, wherein an illumination mode of the surface plasmon photolithography is vertical illumination or off-axis illumination. ### Claim 9 (depends on 1) The photolithography method according to claim 1, wherein a number of slits and a number of lines in the pattern of the second photolithography structure are twice those of the first photolithography structure. ### Claim 10 (depends on 1) The photolithography method according to claim 1, wherein the functional film layer is prepared by using one of Si, SiC, SiO2, Si3N3, Ge, ITO, Al, W, Ag and Au; the functional film layer is prepared by magnetron sputtering deposition, evaporation deposition, chemical vapor deposition or atomic layer deposition; and the functional film layer is etched by ion beam etching, reactive ion etching or inductively coupled plasma etching. ### Claim 11 (depends on 1) The photolithography method according to claim 1, wherein the reflective auxiliary imaging film layer with a thickness of 10 nm to 100 nm is prepared; the first photoresist layer with a thickness of 10 nm to 100 nm is prepared; the second photoresist layer with a thickness of 10 nm to 100 nm is prepared; and the transmissive auxiliary imaging film layer with a thickness of 5 nm to 50 nm is prepared. ### Claim 12 (depends on 1) The photolithography method according to claim 1, wherein the photolithography substrate is a quartz substrate, a silicon substrate, a germanium substrate, a glass substrate, a sapphire substrate, or an organic thin film substrate; the transmissive auxiliary imaging film layer is removed by a removing method of wet removal, tearing removal after physical adhesion, or ion bombardment removal; and the reflective auxiliary imaging film layer and the second photoresist layer which are residual after etching are removed by a chemical reaction method or a dissolution method.