Sub-30nm strained p-channel fin-type field-effect transistors with condensed SiGe source/drain stressors

Strained p-channel fin-type field-effect transistors (FinFETs) with SiGe source and drain (S/D) regions formed by a Ge condensation process is demonstrated. SiGe epitaxial layer was grown on the sidewalls at the S/D regions after a successful removal of both the polysilicon gate and nitride spacer stringer. Condensation of the SiGe at the S/D region was subsequently performed. The novel local Ge condensation not only drives Ge into the Si fin and/or increases the Ge concentration in the S/D regions for enhanced strain effects, but also eliminates the need for S/D recess etch, leading to process simplicity. Compared to a FinFET with uncondensed Si1-xGex S/D, FinFETs with condensed Si1-yGey S/D exhibit 28% higher drive current. Devices with gate lengths down to 26 nm were demonstrated with excellent control of short-channel effects.