# US 2021/0280431 A1 · Pattern formation method and semiconductor device manufacturing method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0280431 A1 - Document ID: US20210280431A1 - Status: Published application - Kind: A1 - Application number: 17/010,989 - Filed: 2020-09-03 - Published: 2021-09-09 - Earliest claimed: 2020-03-04 - Assignees: Kioxia Corporation - Applicants: Kioxia Corporation - Inventors: Yusuke KASAHARA - Web page: https://patentgrep.com/patent/US20210280431A1 ## CPC - H10P 50/73: {using masks for insulating materials} - H10B 43/27: the channels comprising vertical portions, e.g. U-shaped channels - H10P 14/6334: {using decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition (deposition by physical ablation of a target H10P14/6329)} - H10P 14/6342: {Liquid deposition, e.g. spin-coating, sol-gel techniques or spray coating} - H10P 14/683: {carbon-based polymeric organic materials, e.g. polyimides, poly cyclobutene or PVC} - H10P 50/283: {by chemical means} - H10P 50/287: {by chemical means} - H10P 76/405: {characterised by their composition, e.g. multilayer masks} - H10P 95/08: {Planarisation of organic insulating materials} - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H10B: ELECTRONIC MEMORY DEVICES ## Abstract In a pattern formation method, a first organic film is formed on a film to be etched and contains a metal. A second organic film is formed on the first organic film, and has a higher density than a density of the first organic film. The first and second organic films are patterned to form a mask, and the film to be etched is etched using the mask. ## Claims ### Claim 1 A pattern formation method comprising: forming a first organic film on a film to be etched; forming a second organic film on the first organic film, the second organic film having a higher density than a density of the first organic film; patterning the second organic film and the first organic film to form a mask having an opening with a sidewall, the first organic film having an inner side surface exposed at the sidewall; causing a metal to be infiltrated into the first organic film from the inner side surface; and forming a recess portion in the film to be etched using the mask. ### Claim 2 (depends on 1) The pattern formation method according to claim 1, wherein the first organic film is formed from an organic material containing reactive groups having a double bond between a carbon or sulfur atom, and an oxygen atom. ### Claim 3 (depends on 2) The pattern formation method according to claim 2, wherein the first organic film contains more reactive groups than the second organic film. ### Claim 4 (depends on 1) The pattern formation method according to claim 1, wherein the metal is at least one of aluminum (Al), chromium (Cr), hafnium (Hf), indium (In), manganese (Mn), molybdenum (Mo), ruthenium (Ru), tantalum (Ta), titanium (Ti), vanadium (V), tungsten (W), or zirconium (Zr). ### Claim 5 (depends on 1) The pattern formation method according to claim 1, wherein the metal is infiltrated into the first organic film by exposing gas containing metal atoms to the inner side surface of the first organic film. ### Claim 6 (depends on 1) The pattern formation method according to claim 1, wherein the inner side surface of the first organic film is exposed to oxidation gas after exposing the inner side surface to gas containing metal atoms. ### Claim 7 (depends on 1) The pattern formation method according to claim 1, wherein the recess portion is formed using fluorine-containing gas. ### Claim 8 (depends on 1) The pattern formation method according to claim 1, wherein the second organic film is formed on the first organic film by a chemical vapor deposition method. ### Claim 9 (depends on 1) The pattern formation method according to claim 1, wherein the patterning the second organic film and the first organic film is performed using the same etch gas. ### Claim 10 (depends on 1) The pattern formation method according to claim 1, wherein the patterning the second organic film and the first organic film is performed by reactive ion etching. ### Claim 11 (depends on 1) The pattern formation method according to claim 1, wherein the density of the first organic film is less than 1.3 g/m3. ### Claim 12 (depends on 1) The pattern formation method according to claim 1, wherein the density of the second organic film is greater than or equal to 1.3 g/m3. ### Claim 13 (depends on 1) The pattern formation method according to claim 1, wherein the first organic film is formed by spin coating. ### Claim 14 (depends on 1) The pattern formation method according to claim 1, further comprising forming an anti-reflective coating on the second organic film. ### Claim 15 (depends on 14) The pattern formation method according to claim 14, further comprising forming a resist mask on the second organic film. ### Claim 16 A semiconductor device manufacturing method, comprising: forming a film to be etched on a semiconductor substrate; forming a first organic film on the film to be etched; forming a second organic film on the first organic film, the second organic film having a higher density than a density of the first organic film; patterning the second organic film and the first organic film to form a mask having an opening with a sidewall, the first organic film having an inner side surface exposed at the sidewall; causing a metal to be infiltrated into the first organic film from the inner side surface; and etching the film to be etched using the mask, thereby forming a recess portion in the film to be etched. ### Claim 17 (depends on 16) The semiconductor device manufacturing method according to claim 16, wherein the film to be etched is a film having silicon oxide layers and silicon nitride layers alternately stacked.