Method for forming metal semiconductor alloys in contact holes and trenches

摘要

A semiconductor device is provided that includes a gate structure on a channel region of a substrate. A source region and a drain region are present on opposing sides of the channel region. A first metal semiconductor alloy is present on an upper surface of at least one of the source and drain regions. The first metal semiconductor alloy extends to a sidewall of the gate structure. A dielectric layer is present over the gate structure and the first metal semiconductor alloy. An opening is present through the dielectric layer to a portion of the first metal semiconductor alloy that is separated from the gate structure. A second metal semiconductor alloy is present in the opening, is in direct contact with the first metal semiconductor alloy, and has an upper surface that is vertically offset and is located above the upper surface of the first metal semiconductor alloy.

主权项

1. A semiconductor device comprising:
a gate structure on a channel region of a substrate, wherein a source region and a drain region are on opposing sides of said channel region of said substrate; a first metal semiconductor alloy present on an upper surface of at least one of said source region and said drain region; a dielectric layer over said gate structure and said first metal semiconductor alloy, wherein an opening is present through said dielectric layer to a portion of said first metal semiconductor alloy; and a second metal semiconductor alloy that is present in said opening and wherein said second metal semiconductor alloy has an upper surface that directly contacts a bottommost surface of said first metal semiconductor alloy, and wherein said first metal semiconductor alloy and said second metal semiconductor alloy having outer edges that are vertically coincident to sidewall surfaces of said opening.