# US 12,002,679 B2 · High step coverage tungsten deposition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,002,679 B2 - Document ID: US12002679B2 - Status: Granted - Kind: B2 - Application number: 17/601,918 - Filed: 2020-04-07 - Published: 2022-06-09 - Granted: 2024-06-04 - Earliest claimed: 2019-04-11 - Assignees: Lam Research Corporation - Applicants: Lam Research Corporation - Inventors: Michael Bowes; Tsung-Han Yang; Anand Chandrashekar; Xing Zhang - Web page: https://patentgrep.com/patent/US12002679B2 ## CPC - C23C 16/045: {Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates} - H10P 14/418: {the conductive layers comprising transition metals} - C23C 16/14: Deposition of only one other metal element - C23C 16/45527: {characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations} - H10P 14/432: {using selective deposition} - H10W 20/045: {for deposition from the gaseous phase, e.g. for chemical vapour deposition [CVD]} - H10W 20/056: {by filling conductive material into holes, grooves or trenches} - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract Methods of depositing a tungsten nucleation layers that achieve very good step coverage are provided. The methods involve a sequence of alternating pulses of a tungsten-containing precursor and a boron-containing reducing agent, while co-flowing hydrogen (H2) with the boron-containing reducing agent. The H2 flow is stopped prior to the tungsten-containing precursor flow. By co-flowing H2 with the boron-containing reducing agent but not with the tungsten-containing precursor flow, a parasitic CVD component is reduced, resulting in a more self-limiting process. This in turn improves step coverage and conformality of the nucleation layer. Related apparatuses are also provided. ## Claims ### Claim 1 A method comprising: providing a substrate including a feature having an opening in a top surface, a sidewall and a bottom in a chamber; and depositing a tungsten nucleation layer in the feature by performing multiple cycles of: flowing a boron-containing reducing agent pulse in the chamber, wherein the boron-containing reducing agent is adsorbed to the feature sidewall and feature bottom, purging the chamber, flowing a tungsten-containing precursor pulse in the chamber to react with the adsorbed boron-containing reducing agent, and purging the chamber, wherein hydrogen (H2) is flowed during the boron-containing reducing agent pulse and no H2 is flowed during the tungsten-containing precursor pulse, wherein H2 suppresses thermal decomposition of the boron-containing reducing agent and wherein the volumetric flow ratio of the H2 to the boron-containing reducing agent is between 20:1 and 400:1. ### Claim 2 (depends on 1) The method of claim 1, wherein the tungsten nucleation layer is at least 10 Angstroms thick and step coverage throughout the feature is at least 90%, step coverage being the ratio of the thickness of the tungsten nucleation layer at any point in the feature to the thickness of the tungsten nucleation layer at the top surface. ### Claim 3 (depends on 1) The method of claim 1, wherein depositing the nucleation layer further comprises at least one cycle of flowing a silane pulse in the chamber; purging the chamber; flowing a tungsten-containing precursor pulse in the chamber; and purging the chamber, wherein no hydrogen is flowed during the tungsten-containing precursor pulse. ### Claim 4 (depends on 3) The method of claim 3, wherein no hydrogen is flowed during the silane pulse. ### Claim 5 (depends on 3) The method of claim 3, wherein hydrogen is flowed during the silane pulse. ### Claim 6 (depends on 3) The method of claim 3, wherein hydrogen is flowed during the silane pulse. ### Claim 7 (depends on 1) The method of claim 1, wherein the tungsten nucleation layer is between 10 Angstroms and 50 Angstroms thick. ### Claim 8 (depends on 1) The method of claim 1, wherein the substrate temperature is below 350° C. ### Claim 9 (depends on 1) The method of claim 1, wherein the substrate temperature is between about 250° C. and 300° C. ### Claim 10 (depends on 1) The method of claim 1, wherein hydrogen reacts with decomposition byproducts of the boron-containing reducing agent. ### Claim 11 (depends on 1) The method of claim 1, wherein the boron-containing reducing agent pulse in the chamber is flowed into the chamber with an inert carrier gas. ### Claim 12 (depends on 1) The method of claim 1, wherein the boron-containing reducing agent is diborane. ### Claim 13 A method comprising: providing a substrate including a feature having an opening in a top surface, a sidewall and a bottom in a chamber; and depositing a tungsten nucleation layer in the feature by performing multiple cycles of: flowing a boron-containing reducing agent pulse in the chamber, wherein the boron-containing reducing agent is adsorbed to the feature sidewall and feature bottom, purging the chamber, flowing a tungsten-containing precursor pulse in the chamber to react with the adsorbed boron-containing reducing agent, and purging the chamber; and wherein depositing the nucleation layer further comprises at least one cycle of: flowing a silane pulse in the chamber; purging the chamber; flowing a tungsten-containing precursor pulse in the chamber wherein no hydrogen is flowed during the tungsten-containing precursor pulse; and purging the chamber. ### Claim 14 (depends on 13) The method of claim 13, wherein no hydrogen is flowed during the silane pulse. ### Claim 15 A method comprising: providing a substrate including a feature having an opening in a top surface, a sidewall and a bottom in a chamber; and depositing a tungsten nucleation layer in the feature by performing multiple cycles of: flowing a boron-containing reducing agent pulse in the chamber, wherein the boron-containing reducing agent pulse in the chamber is flowed into the chamber with an inert gas and the boron-containing reducing agent is adsorbed to the feature sidewall and feature bottom, purging the chamber, flowing a tungsten-containing precursor pulse in the chamber to react with the adsorbed boron-containing reducing agent, and purging the chamber, wherein hydrogen (H2) is flowed during the boron-containing reducing agent pulse and no H2 is flowed during the tungsten-containing precursor pulse.