Stacked Gate-All-Around Nanosheet pFET with Highly Compressive Strained Si1-xGex Channel
Stacked Gate-All-Around (GAA) nanosheet pFETs with compressively strained Si1-xGex channel have been fabricated to explore their electrical benefits. The Si1-xGex 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 Si1-xGex thickness, Ge fraction, and Si cap thickness on the Si1-xGex NS channel device characteristics. It is found that the compressively strained Si1-xGex 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.