CMOS Beyond Silicon: Vertical GeSn Nanowire MOSFETs

Abstract The continued downscaling of silicon CMOS technology faces big challenges in achieving the required low power consumption. While high mobility channel materials hold promise for improved device performance at low power levels, to date a material system which enables both high mobility n-FETs and p-FETs, that is compatible with Si technology and can be readily integrated into existing fabrication lines is still missing. Here, we present high performance, vertical nanowire gate-all-around FETs based on the GeSn-material system grown on Si. While the p-FET performance is improved by exploiting the small band gap of GeSn as source yielding high injection velocities, the mobility in n-FETs is increased 2.5-fold compared to a Ge reference device, by using GeSn as channel material. The very high potential of the material system for future beyond Si CMOS logic and quantum computing applications is demonstrated via a GeSn inverter and steep switching at cryogenic temperatures, respectively.