Methods of forming semiconductor structures

Abstract

Methods for forming a semiconductor structure and semiconductor structures are described. The method comprises patterning a substrate to form a first opening and a second opening, the substrate comprising an n transistor and a p transistor, the first opening over the n transistor and the second opening over the p transistor; pre-cleaning the substrate; depositing a titanium silicide (TiSi) layer on the n transistor and on the p transistor by plasma-enhanced chemical vapor deposition (PECVD); optionally depositing a first barrier layer on the titanium silicide (TiSi) layer and selectively removing the first barrier layer from the p transistor; selectively forming a molybdenum silicide (MoSi) layer on the titanium silicide (TiSi) layer on the n transistor and the p transistor; forming a second barrier layer on the molybdenum silicide (MoSi) layer; and annealing the semiconductor structure. The method may be performed in a processing chamber without breaking vacuum.