# US 2021/0242032 A1 · Metal-containing passivation for high aspect ratio etch > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0242032 A1 - Document ID: US20210242032A1 - Status: Published application - Kind: A1 - Application number: 17/259,526 - Filed: 2019-08-19 - Published: 2021-08-05 - Earliest claimed: 2018-08-24 - Assignees: Lam Research Corporation - Applicants: Lam Research Corporation - Inventors: Karthik S. COLINJIVADI; Samantha SiamHwa TAN; Shih-Ked LEE; George MATAMIS; Yongsik YU; Yang PAN; Patrick VAN CLEEMPUT; Akhil SINGHAL; Juwen GAO; Raashina HUMAYUN - Web page: https://patentgrep.com/patent/US20210242032A1 ## CPC - H10P 50/283: {by chemical means} - H10P 50/73: {using masks for insulating materials} - H10P 70/234: {the processing being the formation of vias or contact holes} - H10P 72/0462: {characterised by the construction of the processing chambers, e.g. modular processing chambers} - H10P 72/0604: {Process monitoring, e.g. flow or thickness monitoring} - H10P 72/0606: {Position monitoring, e.g. misposition detection or presence detection} - H10P 72/3306: {Horizontal transfer of a single workpiece} - H10P 72/7624: {characterised by the mechanical construction of the susceptor, stage or support} - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract Various embodiments herein relate to methods, apparatus, and systems for etching a feature in a substrate. Typically the feature is etched in a dielectric-containing stack. The etching process involves cyclically etching the feature and depositing a protective film on sidewalls of the partially etched feature. These stages are repeated until the feature reaches its final depth. The protective film may have a particular composition, for example including at least one of a tungsten carbonitride, a tungsten sulfide, tin, a tin-containing compound, molybdenum, a molybdenum-containing compound, a ruthenium carbonitride, a ruthenium sulfide, an aluminum carbonitride, an aluminum sulfide, zirconium, and a zirconium-containing compound. A number of optional steps may be taken including, for example, doping the mask layer, pre-treating the substrate prior to deposition, removing the protective film from the sidewalls, and oxidizing any remaining protective film. ## Claims ### Claim 1 A method of forming an etched feature in a dielectric-containing stack on a substrate, the method comprising: (a) partially etching the feature in the dielectric-containing stack by exposing the substrate to a first plasma comprising an etching reactant; (b) after (a), depositing a protective film on sidewalls of the feature, the protective film comprising at least one of a tungsten carbonitride, a tungsten sulfide, tin, a tin-containing compound, molybdenum, a molybdenum-containing compound, a ruthenium sulfide, an aluminum sulfide, zirconium, and a zirconium-containing compound; and (c) repeating (a)-(b) until the feature is etched to a final depth, wherein the protective film deposited in (b) substantially prevents lateral etch of the feature during (a), and wherein the feature has an aspect ratio of about 5 or greater at its final depth. ### Claim 2 (depends on 1) The method of claim 1, wherein the protective film comprises tungsten carbonitride, tungsten oxide, or tungsten sulfide. ### Claim 3 (depends on 2) The method of claim 2, wherein the protective film comprises tungsten carbonitride. ### Claim 4 (depends on 1) The method of claim 1, wherein the protective film comprises tin, tin oxide, tin nitride, tin carbide, tin carbonitride, or tin sulfide. ### Claim 5 (depends on 4) The method of claim 4, wherein the protective film comprises tin oxide. ### Claim 6 (depends on 1) The method of claim 1, wherein the protective film comprises molybdenum, molybdenum oxide, molybdenum carbide, molybdenum nitride, molybdenum carbonitride, or molybdenum sulfide. ### Claim 7 (depends on 1) The method of claim 1, wherein the protective film comprises a metal sulfide. ### Claim 8 (depends on 1) The method of claim 1, wherein the protective film comprises ruthenium sulfide. ### Claim 9 (depends on 1) The method of claim 1, wherein the protective film comprises aluminum sulfide. ### Claim 10 (depends on 1) The method of claim 1, wherein the protective film comprises zirconium, zirconium oxide, zirconium carbide, zirconium nitride, zirconium carbonitride, or zirconium sulfide. ### Claim 11 (depends on 1) The method of claim 1, wherein (b) comprises depositing the protective film through an atomic layer deposition reaction comprising: (i) exposing the substrate to a first deposition reactant and allowing the first deposition reactant to adsorb onto the sidewalls of the feature; and (ii) after (i), exposing the substrate to a second deposition reactant and reacting the first and second deposition reactants in a surface reaction, thereby forming the protective film on the sidewalls of the feature. ### Claim 12 (depends on 1) The method of claim 1, wherein (b) comprises depositing the protective film through a chemical vapor deposition reaction comprising exposing the substrate to a first deposition reactant and a second deposition reactant simultaneously. ### Claim 13 (depends on 1) The method of claim 1, further comprising doping a mask layer on the dielectric-containing stack prior to (a). ### Claim 14 (depends on 1) The method of claim 1, wherein (a) results in formation of a fluorocarbon-based coating on the sidewalls of the feature, the method further comprising after (a) and before (b), pre-treating the substrate to thereby remove or alter the fluorocarbon-based coating, and wherein pre-treating the substrate comprises exposing the substrate to plasma generated from either (i) a gas comprising N2 and H2, or (ii) a gas comprising O2 and inert gas. ### Claim 15 (depends on 14) The method of claim 14, wherein the protective film comprises tungsten carbonitride. ### Claim 16 (depends on 1) The method of claim 1, wherein (a) results in formation of a fluorocarbon-based coating on the sidewalls of the feature, wherein the protective film comprises tin oxide, and wherein the tin oxide protective film is deposited in (b) directly on the fluorocarbon-based coating formed in (a). ### Claim 17 (depends on 1) The method of claim 1, further comprising removing the protective film from the sidewalls after the feature is fully etched. ### Claim 18 (depends on 1) The method of claim 1, wherein the protective film comprises tungsten carbonitride and is removed by exposing the substrate to H2O2, SCl, or a plasma generated from a gas comprising Cl2O2. ### Claim 19 (depends on 1) The method of claim 1, further comprising exposing the substrate to oxidizing conditions after the feature is fully etched to thereby oxidize any remaining protective film on the sidewalls of the feature. ### Claim 20 An apparatus for forming an etched feature in a dielectric-containing stack on a semiconductor substrate, the apparatus comprising: one or more reaction chambers, wherein at least one reaction chamber is designed or configured to perform etching, and wherein at least one reaction chamber is designed or configured to perform deposition, each reaction chamber comprising: an inlet for introducing process gases to the reaction chamber, and an outlet for removing material from the reaction chamber, and a controller having instructions for causing: (a) partially etching the feature in the dielectric-containing stack by exposing the substrate to a first plasma comprising an etching reactant, wherein (a) is performed in the reaction chamber designed or configured to perform etching; (b) after (a), depositing a protective film on sidewalls of the feature, wherein the protective film comprises at least one of a tungsten carbonitride, a tungsten sulfide, tungsten oxide, tin oxide, tin, a tin-containing compound, molybdenum, and a molybdenum-containing compound, and wherein (b) is performed in the reaction chamber designed or configured to perform deposition; and (c) repeating (a)-(b) until the feature is etched to a final depth, wherein the protective film deposited in (b) substantially prevents lateral etch of the feature during (a), and wherein the feature has an aspect ratio of about 5 or greater at its final depth. ### Claim 21 (depends on 20) The apparatus of claim 20, wherein the reaction chamber designed or configured to perform etching is the same reaction chamber designed or configured to perform deposition, such that both (a) and (b) occur in the same reaction chamber. ### Claim 22 (depends on 20) The apparatus of claim 20, wherein the reaction chamber designed or configured to perform etching is different from the reaction chamber designed or configured to perform deposition, and wherein the controller further comprises instructions to transfer the substrate under vacuum conditions between the reaction chamber designed or configured to perform etching and the reaction chamber designed or configured to perform deposition.