# US 2022/0285167 A1 · Selective barrier metal etching > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0285167 A1 - Document ID: US20220285167A1 - Status: Published application - Kind: A1 - Application number: 17/592,365 - Filed: 2022-02-03 - Published: 2022-09-08 - Earliest claimed: 2021-03-03 - Assignees: Applied Materials, Inc. - Applicants: Applied Materials, Inc. - Inventors: Jonathan SHAW; Gene LEE - Web page: https://patentgrep.com/patent/US20220285167A1 ## CPC - H10P 50/283: {by chemical means} - H01J 37/321: {the radio frequency energy being inductively coupled to the plasma} - H10P 50/267: {using plasmas} - H10W 20/037: {the barrier, adhesion or liner layers being on top of a main fill metal} - H10W 20/063: {by forming conductive members before forming protective insulating material} - H10W 20/0633: {using subtractive patterning of the conductive members} - H01J 2237/334: Etching - H10W 20/425: {Barrier, adhesion or liner layers} - 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) - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract A method for selective barrier metal etching includes performing a hydrogen implantation process, in an inductively coupled plasma (ICP) etch chamber, to chemically reduce an oxidized portion of a barrier metal layer formed within a feature in a metal layer on the barrier metal layer, and performing an etch process, in the ICP etch chamber, to remove the hydrogen implanted portion of the barrier metal layer. ## Claims ### Claim 1 A method for selective barrier metal etching, the method comprising: performing a hydrogen implantation process, in an inductively coupled plasma (ICP) etch chamber, to chemically reduce an oxidized portion of a barrier metal layer formed within a feature in a metal layer on the barrier metal layer; and performing an etch process, in the ICP etch chamber, to remove the hydrogen implanted portion of the barrier metal layer. ### Claim 2 (depends on 1) The method of claim 1, wherein the metal layer comprises ruthenium. ### Claim 3 (depends on 1) The method of claim 1, wherein the barrier metal layer comprises a first layer comprising titanium and a second layer comprising titanium nitride. ### Claim 4 (depends on 1) The method of claim 1, wherein the barrier metal layer comprises a first layer comprising tantalum and a second layer comprising tantalum nitride. ### Claim 5 (depends on 1) The method of claim 1, wherein the hydrogen implantation process comprises directing plasma effluents generated from a hydrogen containing gas towards the oxidized portion of the barrier metal layer. ### Claim 6 (depends on 1) The method of claim 1, wherein the etch process comprises supplying a chlorine containing gas, an inert gas, and a carbon containing gas in the ICP etch chamber. ### Claim 7 (depends on 1) The method of claim 1, wherein the hydrogen implantation process and the etch process remove an outermost atomic layer of the hydrogen implanted portion of the barrier metal layer. ### Claim 8 A method for forming a metal containing feature, the method comprising: performing a first etch process, in an inductively coupled plasma (ICP) etch chamber, to form a feature in a metal layer formed on a metal barrier layer, using an oxygen containing etching gas; performing a hydrogen implantation process, in the ICP etch chamber, to chemically reduce an oxidized portion of the barrier metal layer formed within the feature in the metal layer; and performing a second etch process, in the ICP etch chamber, to remove the hydrogen implanted portion of the barrier metal layer by using a chlorine containing etching gas. ### Claim 9 (depends on 8) The method of claim 8, wherein the metal layer comprises ruthenium. ### Claim 10 (depends on 8) The method of claim 8, wherein the barrier metal layer comprises a first layer comprising titanium and a second layer comprising titanium nitride. ### Claim 11 (depends on 8) The method of claim 8, wherein the barrier metal layer comprises a first layer comprising tantalum and a second layer comprising tantalum nitride. ### Claim 12 (depends on 8) The method of claim 8, wherein the hydrogen implantation process comprises directing plasma effluents generated from a hydrogen containing gas towards the oxidized portion of the barrier metal layer. ### Claim 13 (depends on 8) The method of claim 8, wherein the hydrogen implantation process and the second etch process remove an outermost atomic layer of the hydrogen implanted portion of the barrier metal layer. ### Claim 14 (depends on 8) The method of claim 8, wherein the oxidized portion of the barrier metal layer formed within the feature in the metal layer has a thickness of between 0.5 nm and 5 nm. ### Claim 15 (depends on 8) The method of claim 8, wherein after the first etch process, the feature has an un-etched portion of the metal layer near a top surface of the barrier metal layer within the feature. ### Claim 16 (depends on 8) The method of claim 8, further comprising: performing a third etch process, in the ICP etch chamber, to remove the un-etched portion of the metal layer by using the oxygen containing etching gas, wherein the first etch process and the third etch process are either same or different ### Claim 17 (depends on 15) The method of claim 15, wherein the hydrogen implantation process, the second etch process, and the third etch process are repeated until the un-etched portion of the metal layer is removed substantially. ### Claim 18 A metal containing structure, comprising: a barrier metal layer formed on a substrate; a metal feature formed on the barrier metal layer; and a dielectric feature formed on the metal feature, wherein the metal feature and the dielectric feature have a line width of between 5 nm and 12 nm. ### Claim 19 (depends on 18) The metal containing structure of claim 18, wherein the metal feature comprising ruthenium, and the dielectric feature comprises silicon nitride. ### Claim 20 (depends on 19) The metal containing structure of claim 19, wherein the barrier metal layer comprises (i) a first layer comprising titanium and a second layer comprising titanium nitride, or (ii) a first layer comprising tantalum and a second layer comprising tantalum nitride.