Toward High Performance SiGe Channel CMOS: Design of High Electron Mobility in SiGe nFinFETs Outperforming Si
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 V DD=0.7 V). In addition, the dynamic performance of tensile-strained SiGe CMOS against Si CMOS is evaluated by TCAD simulation based on experimental data.