Structure to Enhance Gate Induced Strain Effect in Multigate Devices

摘要

A FinFet device structure provided with a thin layer of polycrystalline silicon having stress containing material, including a high Ge percentage silicon germanium film and/or a high stress W film on top of a polycrystalline silicon film. Space between the fins enables the stressor films to be positioned closer to the transistor channel. The improved proximity of the stress containing material to the transistor channel and the enhanced stress couple the efficiency defines a ratio between the stress level in the stressor film and stress transfer to the channel for mobility enhancement. The stress level is further enhanced by patterning by removal of the n-type workfunction metal from the p-FinFET. Following the stripping off the soft or hard mask, the p-type workfunction metal ends positioned in the n- and p-FinFET regions. The freed space specifically for p-FinFet between the fins achieves an even higher stressor coupling to further boost the carrier mobility.

主权项

1. A structure formed a semiconductor device comprising:
a plurality of fins on a substrate; a gate stack over said fins with a source region and a drain region exposed; a thin layer of polycrystalline silicon over said fins; an epitaxial having a high GE percentage silicon germanium film on top of said polycrystalline silicon; and a transistor channel wrapping said gate stack around said fins.