CMOS FinFETs MOS devices MOSFET ON-state Sentaurus TCAD SiGe Silicon-Germanium source/drain (SiGe S/D) ambipolar band-to-band tunneling (BTBT) bulk NMOS devices buried channel compact model compact models device simulation doping incorporation drain engineered electrostatic discharge (ESD) etching simulation ferroelectrics field effect transistor field-effect transistor fin field effect transistor (FinFET) flux calculation high-? dielectric high-k highly miniaturized transistor structure indium selenide inversion channel layout