FINFET CHANNEL STRESS USING TUNGSTEN CONTACTS IN RAISED EPITAXIAL SOURCE AND DRAIN

摘要

Performance of a FinFET is enhanced through a structure that exerts physical stress on the channel. The stress is achieved by a combination of tungsten contacts for the source and drain, epitaxially grown raised source and raised drain, and manipulation of aspects of the tungsten contact deposition resulting in enhancement of the inherent stress of tungsten. The stress can further be enhanced by epitaxially re-growing the portion of the raised source and drain removed by etching trenches for the contacts and/or etching deeper trenches (and corresponding longer contacts) below a surface of the fin.

主权项

1. A method, comprising:
providing an intermediate semiconductor structure of a FinFET, the structure comprising a semiconductor substrate and at least one fin coupled to the substrate, the at least one fin comprising a source region, a drain region and a channel between the source region and the drain region; epitaxially growing a raised source in the source region and a raised drain in the drain region; etching a trench in the raised source and the raised drain; and creating tungsten contacts in the raised source trench and raised drain trench, wherein the tungsten contacts have a stress different from an inherent stress of tungsten.