TRANSISTOR STRAIN-INDUCING SCHEME

摘要

A transistor device includes a gate structure disposed over a channel region of a semiconductor substrate. A source/drain recess is arranged in the semiconductor substrate alongside the gate structure. A doped silicon-germanium (SiGe) region is disposed within the source/drain recess and has a doping type which is opposite to that of the channel. An un-doped SiGe region is also disposed within the source/drain recess. The un-doped SiGe region underlies the doped SiGe region and comprises different germanium concentrations at different locations within the source/drain recess.

主权项

1. A method of forming a transistor device, comprising:
forming a substantially v-shaped source/drain recess within a semiconductor substrate; forming outer un-doped strain-inducing regions in outermost lateral tips of the substantially v-shaped source/drain recess, the outer un-doped strain-inducing regions having a first strain-inducing component at a first concentration; and forming an intermediate un-doped strain-inducing region which extends along a lower angled sidewall of the substantially v-shaped source/drain recess and which extends between the outer un-doped strain-inducing regions without completely filling the substantially v-shaped source/drain recess, the intermediate un-doped strain-inducing region having a second strain-inducing component at a second concentration that differs from the first concentration.