High Performance SiGe Nanowire Tunnel FETs: Low Temperature Characterization for Device Process Optimization

This paper presents SiGe nanowire tunneling field effect transistors (TFETs) cointegrated with MOSFETs. The process is detailed, and the differences between TFET injection (Band-to-Band Tunneling or BTBT) and MOSFET thermionic injection are outlined. The fabricated TFETs exhibit record ON-current performances at room temperature, three times higher than previous state of the art. Low-temperature measurements are conducted to clarify the device physics. It is shown that subthreshold slope degradation is a result of trap assisted tunneling; careful control of the defect-inducing process steps could lead to slopes lower than 60mV/dec at room temperature, without degradation of ON-state current.