Stacked Gate-All-Around Nanosheet pFET with Highly Compressive Strained Si 1-x Ge x Channel

Stacked Gate-All-Around (GAA) nanosheet pFETs with compressively strained Si 1-x Ge x channel have been fabricated to explore their electrical benefits. The Si 1-x Ge x NS channel structure with high crystalline quality and 1GPa compressive stress has been realized for the first time. Systematic study has been performed to understand the effect of epitaxial Si 1-x Ge x thickness, Ge fraction, and Si cap thickness on the Si 1-x Ge x NS channel device characteristics. It is found that the compressively strained Si 1-x Ge x NS channel provides a 100% uplift in peak hole mobility with a corresponding channel resistance reduction of 40% while maintaining an excellent subthreshold slope of below 70 mV/dec.