Structure and method to form liner silicide with improved contact resistance and reliablity

摘要

A contact structure with improved contact resistance and reliability is provided by forming an inner spacer between a contact liner and dielectric layers laterally surrounding the contact structure. The inner spacer severs as a barrier to prevent diffusion of metals from the contact liner into the dielectric layers.

主权项

1. A method of forming a semiconductor structure comprising:
forming a plurality of contact openings through at least one contact level dielectric layer and a portion of an interlevel dielectric (ILD) layer, the plurality of contact openings exposing portions of an epitaxial source region and an epitaxial drain region of at least one semiconductor device; forming an inner spacer on a sidewall of each of the plurality of contact openings, wherein an entirety of the inner spacer contacts the sidewall of each of the plurality of contact openings; forming a contact liner material layer on the inner spacer and bottom surfaces of the plurality of contact openings, wherein bottom portions of the contact liner material layer in the plurality of contact openings react with exposed portions of the epitaxial source region and the epitaxial drain region to form liner silicide portions; and forming a contact conductor layer to fill remaining volumes of the plurality of contact openings.