# US 7,407,875 B2 · Low resistance contact structure and fabrication thereof

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- Number: US 7,407,875 B2
- Document ID: US7407875B2
- Status: Granted
- Kind: B2
- Application number: 11/470,349
- Filed: 2006-09-06
- Published: 2008-03-06
- Granted: 2008-08-05
- Earliest claimed: 2006-09-06
- Assignees: International Business Machines Corporation
- Inventors: Keith Kwong Hon Wong; Patrick W. DeHaven; Sadanand V. Deshpande; Anita Madan
- Web page: https://patentgrep.com/patent/US7407875B2

## CPC

- H10W 20/035: {combinations of barrier, adhesion or liner layers, e.g. multi-layered barrier layers}
- H10W 20/048: {by using plasmas or gaseous environments, e.g. by nitriding}
- H10W 20/40: Interconnections external to wafers or substrates, e.g. back-end-of-line [BEOL] metallisations or vias connecting to gate electrodes
- H10P 14/43: Chemical deposition, e.g. chemical vapour deposition [CVD]
- H10P 14/44: Physical vapour deposition [PVD]
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

Embodiments of the present invention provide a method of fabricating a contact structure in a layer of dielectric material between a semiconductor device and a back-end-of-line interconnect. The method includes creating at least one contact opening in said layer of dielectric material; forming a first TiN film through a chemical-vapor deposition process, said first TiN film lining said contact opening; and forming a second TiN film through a physical vapor deposition process, said second TiN film lining said first TiN film. A contact structure fabricated according to embodiments of the invention is also provided.

## Claims

### Claim 1

A method of fabricating a contact structure in a layer of dielectric material between a semiconductor device and a back-end-of-line interconnect, the method comprising:
creating at least one contact opening in said layer of dielectric material, said at least one contact opening exposes a suicide contact surface of said semiconductor device;
forming a first TiN film through a chemical-vapor deposition process, said first TiN film lining said contact opening; and
forming a second TiN film through a physical vapor deposition process, said second TiN film lining said first TiN film,
wherein forming said second TiN film comprises directionally sputtering a layer of Ti onto said first TiN film and subsequently converting said layer of Ti into said second TiN film though a post-deposition process; and
wherein said post-deposition process comprises a forming gas annealing treatment, using a gas mixture of about 5-10% atomic H2 and 90-95% atomic N2, at a temperature of about 500° C. to about 650° C., for about 15 minutes to about 1 hour.

### Claim 2

A method of fabricating a semiconductor structure, the method comprising:
fabricating at least one semiconductor device; and
fabricating one or more stud contact structure interfacing with one or more contact areas of said semiconductor device,
wherein said fabricating one or more stud contact structure comprises:
forming one or more openings in a layer of dielectric material, at least one of said openings exposes a silicide contact surface of said semiconductor device;
applying a chemical vapor deposition (CVD) process to create a first TiN liner over said at least one of said openings;
applying a physical vapor deposition (PVD) process to create a second TiN liner over said first TiN liner; and
filling said at least one of said openings, on top of said second TiN liner, with a conductive material.
wherein creating said second TiN liner comprises sputter-depositing a layer of Ti onto said first TiN liner, and converting said layer of Ti into said second TiN liner through a forming gas annealing process, using a gas mixture of about 5-10% atomic H2 and 90-95% atomic N2, at a temperature of about 500° C. to about 650° C, and for about 15 minutes to about 1 hour.

### Claim 3

A method of creating a structure, comprising:
fabricating at least one contact opening in a layer of dielectric material on top of a semiconductor device, said contact opening exposes a silicide contact surface of said semiconductor device;
forming a first TiN film through a chemical vapor deposition process, said first TiN film lining said contact opening;
forming a second TiN film through a physical vapor deposition process, said second TiN film lining said first TiN film; and
filling said contact opening, on top of said second TiN film, with a conductive material,
wherein forming said second TiN liner comprises directionally sputtering Ti onto said first TiN liner and subsequently converting said sputtered Ti into said second TiN liner through a post-deposition treatment.