Toward High Performance SiGe Channel CMOS: Design of High Electron Mobility in SiGe nFinFETs Outperforming Si

Abstract

For the first time, high electron mobility in tensile-strained SiGe channel nFinFETs outperforming Si is reported to explore the feasibility of high performance SiGe CMOS. To examine the electron mobility behaviors in SiGe channel, a series of tensile-strained SiGe nFinFETs are fabricated on various strain relaxed buffer layers by taking into account the minimum threading dislocation density and strain engineering. For SiGe (Ge>20%) nFinFETs, we identify the existence of additional electron trapping site close to the conduction band edge in IL/HK, leading to the abnormal Vt shift, PBTI degradation, and low electron mobility. We also fabricated short-channel SiGe nFinFETs, which exhibit excellent cut-off behavior and electrostatics (SS ~65mV/dec and DIBL ~18mV at VDD=0.7V). In addition, the dynamic performance of tensile-strained SiGe CMOS against Si CMOS is evaluated by TCAD simulation based on experimental data.