# US 8,785,320 B2 · Structure and process for metallization in high aspect ratio features > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,785,320 B2 - Document ID: US8785320B2 - Status: Granted - Kind: B2 - Application number: 13/901,886 - Filed: 2013-05-24 - Published: 2013-09-26 - Granted: 2014-07-22 - Earliest claimed: 2008-02-21 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Chih-Chao Yang; Fenton R. McFeely - Web page: https://patentgrep.com/patent/US8785320B2 ## CPC - H10P 14/6548: {by forming intermediate materials, e.g. capping layers or diffusion barriers} - H10W 20/021: {of interconnections within wafers or substrates} - H10W 20/032: {of conductive barrier, adhesion or liner layers} - H10W 20/036: {the barrier, adhesion or liner layers being within a main fill metal} - H10W 20/056: {by filling conductive material into holes, grooves or trenches} - H10W 20/057: {by selectively depositing, e.g. by using selective CVD or plating} - H10W 20/40: Interconnections external to wafers or substrates, e.g. back-end-of-line [BEOL] metallisations or vias connecting to gate electrodes - H10W 20/425: {Barrier, adhesion or liner layers} - H10W 20/4441: {the principal metal being a refractory metal} - 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 A high aspect ratio metallization structure is provided in which a noble metal-containing material is present at least within a lower portion of a contact opening located in a dielectric material and is in direct contact with a metal semiconductor alloy located on an upper surface of a material stack of at least one semiconductor device. In one embodiment, the noble metal-containing material is plug located within the lower region of the contact opening and an upper region of the contact opening includes a conductive metal-containing material. The conductive metal-containing material is separated from plug of noble metal-containing material by a bottom walled portion of a U-shaped diffusion barrier. In another embodiment, the noble metal-containing material is present throughout the entire contact opening. ## Claims ### Claim 1 A method of fabricating a semiconductor structure comprising: providing a structure including at least one semiconductor device located on a surface of a semiconductor substrate, said at least one semiconductor device including at least a material stack having an upper surface that is comprised of a metal semiconductor alloy; forming a single layer of dielectric material on said surface of said semiconductor substrate, said single layer of dielectric material including a contact opening that extends to the upper surface of said material stack, said contact opening having an aspect ratio of greater than 3:1; and partially filling said contact opening in said single layer of dielectric material with at least a metal-containing material that is resistant to corrosion and oxidation and is lower in the Galvanic Series than said metal semiconductor alloy utilizing a selective deposition process selected from chemical vapor deposition, plasma enhanced chemical vapor deposition, atomic layer deposition, and plasma enhanced atomic layer deposition, said metal-containing material is present within a lower region of said contact opening and is in direct contact with said upper surface of said material stack, wherein said metal-containing material has a top surface located beneath a top surface of said single layer of dielectric material. ### Claim 2 (depends on 1) The method of claim 1 further comprising forming at least a U-shaped diffusion barrier and a conductive metal-containing material within said contact opening, said conductive metal-containing material is located within an upper portion of said contact opening and is separated from said metal-containing material by a bottom wall portion of at least said U-shaped diffusion barrier. ### Claim 3 (depends on 2) The method of claim 2 further comprising forming a U-shaped plating seed layer present within said contact opening, said U-shaped plating layer is present between said U-shaped diffusion barrier and said conductive metal-containing layer. ### Claim 4 (depends on 1) The method of claim 1 wherein said metal-containing material is a plug and comprises one of Ru, Rh, Ir, Pt, Co, Pd and alloys thereof. ### Claim 5 (depends on 2) The method of claim 2 wherein said conductive metal-containing material is one of Cu, W, and Al, and said diffusion barrier comprises one of Ta(N), Ti(N), W(N), and Ru(N). ### Claim 6 (depends on 2) The method of claim 2 wherein said conductive metal-containing material has an uppermost surface that is coplanar with an uppermost surface of said single layer of dielectric material. ### Claim 7 (depends on 1) The method of claim 1 wherein said contact opening is formed by lithography and etching. ### Claim 8 A method of forming a semiconductor structure comprising: providing a structure including at least one semiconductor device located on a surface of a semiconductor substrate, said at least one semiconductor device including at least a material stack having an upper surface that is comprised of a metal semiconductor alloy; forming a single layer of dielectric material on said surface of said semiconductor substrate, said single layer of dielectric material including a contact opening that extends to the upper surface of said material stack, said contact opening having an aspect ratio of greater than 3:1; partially filling said contact opening in said single layer of dielectric material with at least a metal-containing material that is resistant to corrosion and oxidation and is lower in the Galvanic Series than said metal semiconductor alloy, said metal-containing material is present within a lower region of said contact opening and is in direct contact with said upper surface of said material stack; forming at least a U-shaped diffusion barrier and a conductive metal-containing material within said contact opening, said conductive metal-containing material is located within an upper portion of said contact opening and is separated from said metal-containing material by a bottom wall portion of at least said U-shaped diffusion barrier, and said conductive metal-containing material has an uppermost surface that is coplanar with an uppermost surface of said single layer of dielectric material. ### Claim 9 (depends on 8) The method of claim 8 further comprising forming a U-shaped plating seed layer within said contact opening, said U-shaped plating layer is present between said U-shaped diffusion barrier and said conductive metal-containing layer. ### Claim 10 (depends on 8) The method of claim 8 wherein said metal-containing material is a plug and comprises one of Ru, Rh, Ir, Pt, Co, Pd and alloys thereof. ### Claim 11 (depends on 8) The method of claim 8 wherein said conductive metal-containing material is one of Cu, W, and Al, and said diffusion barrier comprises one of Ta(N), Ti(N), W(N), and Ru(N). ### Claim 12 (depends on 8) The method of claim 8 wherein said metal-containing material is formed by a selective deposition process selected from chemical vapor deposition, plasma enhanced chemical vapor deposition, atomic layer deposition, and plasma enhanced atomic layer deposition. ### Claim 13 (depends on 8) The method of claim 8 wherein said contact opening is formed by lithography and etching. ### Claim 14 (depends on 8) The method of claim 8 wherein said metal semiconductor alloy is formed by a salicidation process. ### Claim 15 (depends on 8) The method of claim 8 wherein said aspect ratio is greater than 10:1. ### Claim 16 (depends on 8) The method of claim 8 wherein noble metal-containing material is void of any key-hole seam defects. ### Claim 17 (depends on 8) The method of claim 8 wherein said partially filling said contact opening with at least said metal-containing material comprises a timed deposition process. ### Claim 18 (depends on 8) The method of claim 8 wherein said partially filling said contact opening with at least said metal-containing material comprises deposition and etching.