Enhanced Hole Transport in Short-Channel Strained-SiGe p-MOSFETs

Abstract

Hole mobility and velocity are extracted from scaled strained-Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.45</sub> Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.55</sub> channel p-MOSFETs on insulator. Devices have been fabricated with sub-100-nm gate lengths, demonstrating hole mobility and velocity enhancements in strained- Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.45</sub> Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.55</sub> channel devices relative to Si. The effective hole mobility is extracted utilizing the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dR</i> / <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dL</i> method. A hole mobility enhancement is observed relative to Si hole universal mobility for short-channel devices with gate lengths ranging from 65 to 150 nm. Hole velocities extracted using several different methods are compared. The hole velocity of strained-SiGe p-MOSFETs is enhanced over comparable Si control devices. The hole velocity enhancements extracted are on the order of 30%. Ballistic velocity simulations suggest that the addition of (110) uniaxial compressive strain to Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.45</sub> Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.55</sub> can result in a more substantial increase in velocity relative to relaxed Si.