Stacked Gate-All-Around Nanosheet pFET with Highly Compressive Strained Si<sub>1-x</sub>Ge<sub>x</sub> Channel
Shinichi Mochizuki, Maruf Bhuiyan, Huimei Zhou, J. Zhang, Erin Stuckert, J. Li, Kai Zhao, M. Wang, Veeraraghavan Basker, N. Loubet, Dechao Guo, Bala Haran, H. Bu
Abstract
Stacked Gate-All-Around (GAA) nanosheet pFETs with compressively strained Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> channel have been fabricated to explore their electrical benefits. The Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> 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 <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> thickness, Ge fraction, and Si cap thickness on the Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> NS channel device characteristics. It is found that the compressively strained Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> 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.