Ge Nanowire FETs with HfZrOx Ferroelectric Gate Stack Exhibiting SS of Sub-60 mV/dec and Biasing Effects on Ferroelectric Reliability

Abstract

Ge nanowire (NW) FETs exhibiting subthreshold swing (SS) of 54 mV/dec at room temperature are demonstrated with ferroelectric HfZrOx (FE-HZO) gate stack for the first time. I-ON/I-OFF ratios higher than 10(7) and 10(6) for p- and n-NWFETs, respectively, have been achieved by adopting the gate-all-around (GAA) configuration. Electrical biasing effects on the HZO ferroelectric reliability have been systematically investigated in this work. It is found that the polarization behavior will degrade with electrical stress time and can be recovered. The Ge HZO FinFET CMOS inverter shows experimentally voltage gain of 24.8 V/V.