High-Performance $\hbox{GeO}_{2}/\hbox{Ge}$ nMOSFETs With Source/Drain Junctions Formed by Gas-Phase Doping

Abstract

We reveal that the MOVPE-based gas-phase doping can yield lower arsenic diffusion constant and lower leakage current n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> /p junctions in Ge compared with conventional ion-implantation doping. Thus, the gas-phase doping is quite effective for realizing high-performance Ge n-channel MOSFETs. By using gas-phase doping for source/drain junction formation, the (100) GeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Ge nMOSFETs have achieved high electron mobility of 1020 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /V·s while maintaining low junction leakage current and high I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</sub> /I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</sub> ratio of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> . Furthermore, the (110) GeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Ge nMOSFETs have also shown high electron mobility and high I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</sub> /I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</sub> ratio.