Titanium silicide formation in a narrow source-drain contact
AssigneeGlobalfoundries Inc.
InventorsMin Gyu Sung, Kwanyong Lim, Hiroaki Niimi
Life of this patent
Estimating the term…
Abstract
Aspects of the present invention relate to approaches for forming a narrow source-drain contact in a semiconductor device. A contact trench can be etched to a source-drain region of the semiconductor device. A titanium liner can be deposited in this contact trench such that it covers substantially an entirety of the bottom and walls of the contact trench. An x-metal layer can be deposited over the titanium liner on the bottom of the contact trench. A titanium nitride liner can then be formed on the walls of the contact trench. The x-metal layer prevents the nitriding of the titanium liner on the bottom of the contact trench during the formation of the nitride liner.
Claims20
A semiconductor device, formed via a process, comprising:
- forming a source-drain region, a replacement metal gate, and an inter-layer dielectric layer on a substrate;
- etching a contact trench that is less than 30 nm in width through the inter-layer dielectric layer to the source-drain region;
- depositing a titanium liner in the contact trench, the titanium liner covering substantially an entirety of a bottom and walls of the contact trench;
- depositing an x-metal layer over the titanium liner on the bottom of the contact trench, wherein the x-metal layer comprises at least one of:
- platinum, hafnium, cobalt, nickel, or tungsten;
- forming a titanium nitride liner on substantially an entirety of the walls of the contact trench, and
- forming a tungsten contact to the source-drain region in the contact trench,
- wherein the x-metal layer prevents a nitriding of the titanium liner on the bottom of the contact trench, and
- wherein the titanium nitride liner binds the tungsten contact to the walls of the contact trench.
A semiconductor device, comprising:
- a source-drain region, a metal gate, and an inter-layer dielectric layer on a substrate;
- a contact trench through the inter-layer dielectric layer to the source-drain region;
- a titanium liner in the contact trench, the titanium liner covering substantially an entirety of a bottom of the contact trench, wherein the titanium liner is not nitrided;
- an x-metal layer over the titanium liner on the bottom of the contact trench;
- a titanium nitride liner directly contacting the inter-layer dielectric on substantially an entirety of the walls of the contact trench, and
- a contact to the source-drain region in the contact trench and bound by the titanium nitride liner to the walls of the contact trench.
A semiconductor device, comprising:
- a source-drain region comprising silicon, a metal gate, and an inter-layer dielectric layer on a substrate;
- a contact trench through the inter-layer dielectric layer to the source-drain region;
- a titanium liner in the contact trench, the titanium liner covering substantially an entirety of a bottom of the contact trench;
- an x-metal layer over the titanium liner on the bottom of the contact trench;
- a titanium nitride liner directly contacting the inter-layer dielectric on substantially an entirety of the walls of the contact trench,
- a contact to the source-drain region in the contact trench and bound by the titanium nitride liner to the walls of the contact trench;
- and
- a titanium silicide between the titanium liner on the bottom of the contact trench and the source-drain region.
Dependencies are inferred from the claim text.