Nonideality of Negative Capacitance Ge Field-Effect Transistors Without Internal Metal Gate

We demonstrate negative capacitance(NC) Ge field-effect transistors (FETs) utilizing the TaN/HfZrOx/SiO2 gate stack. Typical characteristics of NC transistors, including the sub-60 mV/decade subthreshold swing (SS), the gate capacitance CG peak, and the negative differential resistance effect are achieved in NC Ge FETs without internal metal gate. Significant CG peak, as the evidence of NC effect ...