US 6,632,736 B2Granted

Method of forming low-resistance contact to silicon having a titanium silicide interface and an amorphous titanium carbonitride barrier layer

AssigneeMicron Technology, Inc.

InventorsGurtej S. Sandhu, Trung T. Doan, Tyler A. Lowrey

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Abstract

A contact structure incorporating an amorphous titanium nitride barrier layer formed via low-pressure chemical vapor deposition (LPCVD) utilizing tetrakis-dialkylamido-titanium, Ti(NMe2)4, as the precursor. The contact structure is fabricated by etching a contact opening through an dielectric layer down to a diffusion region to which electrical contact is to be made. Titanium metal is deposited over the surface of the wafer so that the exposed surface of the diffusion region is completely covered by a layer of the metal. At least a portion of the titanium metal layer is eventually converted to titanium silicide, thus providing an excellent conductive interface at the surface of the diffusion region. A titanium nitride barrier layer is then deposited using the LPCVD process, coating the walls and floor of the contact opening. Chemical vapor deposition of polycrystalline silicon or of a metal follows.

Claims10

Dependent claims

A process of making a contact structure for an integrated circuit comprising:

providing a silicon region on a surface of a semiconductor wafer for making electrical contact thereto;
depositing a dielectric layer over at least a portion of the silicon region;
etching a contact opening through the dielectric layer for exposing a portion of the silicon region, the contact opening having a side wall;
depositing a titanium metal layer within the contact opening for covering the portion of the silicon region exposed by the contact opening;
depositing a predominantly amorphous titanium carbonitride film having predominantly no definite crystalline structure and having predominantly no crystalline titanium therein, the predominantly amorphous titanium carbonitride film for lining the side wall of the contact opening to overlay the titanium metal layer covering the portion of the silicon region exposed by the contact opening;
and
filling at least a portion of the contact opening using a conductive material.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/921,615Filed 3 Aug 2001 · continuation
Priority: 12 Jun 1992
Published: US 2001/0055875 A127 Dec 2001
Granted: 14 Oct 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification14 codes

H10W 20/047
Of conductive barrier, adhesion or liner layers: by introducing additional elements therein
C23C 16/34
Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides: nitrides
H10D 64/0112
To Group IV semiconductors: using conductive layers comprising silicides
H10D 64/01125
Using conductive layers comprising silicides: the silicides being formed by chemical reaction with the semiconductor after the contact hole formation

Family

Application07/898,059Parent of this continuation · filed 12 Jun 1992
Application08/228,795Parent of this continuation-in-part · filed 15 Apr 1994
Application08/509,708Parent of this continuation · filed 31 Jul 1995
Application09/012,685Parent of this continuation · filed 23 Jan 1998
US 5,723,382 AParent of this continuation · filed 3 Mar 1998
Application09/495,534Parent of this continuation · filed 31 Jan 2000
US 6,081,034 AParent of this continuation · filed 27 Jun 2000
US 6,291,340 B1Parent of this continuation · filed 18 Sep 2001
US 2001/0055875 A1Pre-grant publication · published 27 Dec 2001
Application08/509,708Parent of this continuation-in-part
Application08/228,795Parent of this continuation
US 6,632,736 B2This patent

From the US filing history. Foreign family members aren’t listed.