High-Performance Ultrathin Body c-SiGe Channel FDSOI pMOSFETs Featuring SiGe Source and Drain: $V_{rm th}$ Tuning, Variability, Access Resistance, and Mobility Issues

摘要

We report on ultrascaled $(L_{G}=23~{rm nm})$ compressively strained SiGe-based FDSOI pMOSFET with ultrathin body. The devices have been fabricated using a high-K metal gate (TiN/HfSiON) process flow. SiGe channels (3.4 nm) have been epitaxially grown on 3-nm thick 300-mm SOI wafers and combined with embedded ${rm Si}_{0.7}{rm Ge}_{0.3}({:}B)$ raised source and drain (RSD) for $V_{rm th,p}$ tuning and smart strain management. In-depth electrical characterizations point out the ${+}{120}hbox{-}{rm mV}~V_{rm th,p}$ tuning, the excellent short-channel, and DIBL control (similar to SOI reference), and show for the first time extremely low variability for SiGe-based FD pMOSFETs. Furthermore, we investigate hole-transport properties as a function of gate length and temperature and demonstrate 60% $R_{rm access}$ reduction with SiGe RSD and ${+}{rm 330%}$ mobility enhancement at 23-nm gate length with respect to 7-nm thick SOI reference.