# US 12,009,219 B2 · Substrate processing method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,009,219 B2 - Document ID: US12009219B2 - Status: Granted - Kind: B2 - Application number: 17/553,879 - Filed: 2021-12-17 - Published: 2022-06-23 - Granted: 2024-06-11 - Earliest claimed: 2020-12-17 - Assignees: Tokyo Electron Limited - Applicants: Tokyo Electron Limited - Inventors: Yusuke Takino; Takayuki Hoshi - Web page: https://patentgrep.com/patent/US12009219B2 ## CPC - H10P 50/244: {comprising alternated and repeated etching and passivation steps} - H01J 37/321: {the radio frequency energy being inductively coupled to the plasma} - H10P 50/242: {of Group IV materials} - H10P 50/283: {by chemical means} - H10P 50/691: {for Group IV materials or Group III-V materials} - H01J 2237/334: Etching - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract A plasma processing method includes: (a) providing a substrate having an etching target film with a recess formed therein, on a substrate support; (b) forming a protective film on a side wall of the recess; (c) after (b), generating plasma from a processing gas to etch a bottom of the recess; and (d) performing a sequence including (b) and (c) one or more times. The step (c) includes a first stage of etching the bottom of the recess while suppressing a formation of a shoulder portion caused when reaction by-products produced by the etching adhere to the side wall, and a second stage of further etching the bottom of the recess in a state where a temperature of the substrate support is controlled to −40° C. or lower, after the first stage. ## Claims ### Claim 1 A plasma processing method comprising: (a) providing a substrate having an etching target film with a recess formed therein, on a substrate support; (b) forming a protective film on a side wall of the recess; (c) after (b), generating plasma from a processing gas to etch a bottom of the recess; and (d) performing a sequence including (1)) and (c) one or more times, wherein (c) includes (c−1) etching the bottom of the recess while suppressing a formation of a shoulder portion caused when by-products produced by the etching adhere to the side wall, and (c−2) further etching the bottom of the recess in a state where a temperature of the substrate support is controlled to −40° C. or lower, after (c−1). ### Claim 2 (depends on 1) The substrate processing method according to claim 1, wherein the formation of the shoulder portion is suppressed by suppressing the by-products from adhering to the side wall or by removing the by-products adhering to the side wall. ### Claim 3 (depends on 1) The substrate processing method according to claim 1, wherein in (c−1), the etching is performed in a state where the temperature of the substrate support is set to a temperature higher than −40° C. ### Claim 4 (depends on 1) The substrate processing method according to claim 1, wherein the etching target film is a silicon-containing film, the processing gas includes a halogen-containing gas that contains no carbon atoms and nitrogen atoms, and an oxygen-containing gas, in (c−1), the etching is performed in a state where a ratio of a flow rate of the oxygen-containing gas to a total flow rate of the halogen-containing gas and the oxygen-containing gas is set to a first ratio, and in (c−2), the etching is performed in a state where the ratio is set to a second ratio larger than the first ratio. ### Claim 5 (depends on 4) The substrate processing method according to claim 4, wherein the halogen-containing gas includes at least one gas selected from a group consisting of SF6 gas, Cl2 gas, and HBr gas. ### Claim 6 (depends on 4) The substrate processing method according to claim 4, wherein the oxygen-containing gas includes O2 gas. ### Claim 7 (depends on 4) The substrate processing method according to claim 4, wherein the silicon-containing film includes a silicon film or a silicon germanium film. ### Claim 8 (depends on 4) The substrate processing method according to claim 4, wherein the first ratio is 35 vol % or less. ### Claim 9 (depends on 1) The substrate processing method according to claim 1, wherein in (a), the substrate with the recess formed therein is provided by etching the etching target film in a state where the temperature of the substrate support is controlled to −40° C or lower, and an etching condition in (a) is same as an etching condition in (c−2). ### Claim 10 (depends on 1) The substrate processing method according to claim 1, wherein a time period of (c−2) is six times or less a time period of (c−1). ### Claim 11 (depends on 1) The substrate processing method according to claim 1, wherein an etching depth of the recess etched in (c−1) is 1 μm or less. ### Claim 12 (depends on 1) The substrate processing method according to claim 1, wherein in (c), (c−1) is switched to (c−2) in a state where plasma is generated. ### Claim 13 (depends on 1) The substrate processing method according to claim 1, wherein (a) to (d) are performed in site. ### Claim 14 (depends on 1) The substrate processing method according to claim 1, wherein the substrate includes a mask on the etching target film, and the protective film has a first thickness on the side wall and a second thickness smaller than the first thickness on the bottom of the recess and a surface of the mask. ### Claim 15 (depends on 1) The substrate processing method according to claim 1, wherein the processing gas includes a halogen-containing gas that contains no carbon atoms and nitrogen atoms, and an oxygen-containing gas, and in (c−1) and (c−2), a ratio of a flow rate of the oxygen-containing gas to a total flow rate of the halogen-containing gas and the oxygen-containing gas is larger than 35 vol %.