Hump Effects of Germanium/Silicon Heterojunction Tunnel Field-Effect Transistors

Abstract

The hump effects of germanium/silicon heterojunction tunnel field-effect transistors are discussed. Simulation results show that they are originated when indirect band-to-band tunneling is converted into direct one as gate voltage (V-g) increases. In order to suppress the hump effects, two ideas are proposed. First, the length of intrinsic-germanium channel (L-Ge) is optimized using a novel process flow. Second, gate-to-channel coupling is improved by increasing source doping concentration (N-S).