Exploring SiSn as a performance enhancing semiconductor: A theoretical and experimental approach

Abstract

We present a novel semiconducting alloy, silicon-tin (SiSn), as channel material for complementary metal oxide semiconductor (CMOS) circuit applications. The material has been studied theoretically using first principles analysis as well as experimentally by fabricating MOSFETs. Our study suggests that the alloy offers interesting possibilities in the realm of silicon band gap tuning. We have explored diffusion of tin (Sn) into the industry's most widely used substrate, silicon (100), as it is the most cost effective, scalable and CMOS compatible way of obtaining SiSn. Our theoretical model predicts a higher mobility for p-channel SiSn MOSFETs, due to a lower effective mass of the holes, which has been experimentally validated using the fabricated MOSFETs. We report an increase of 13.6% in the average field effect hole mobility for SiSn devices compared to silicon control devices.