GeSn channel nMOSFETs: Material potential and technological outlook

Semiconducting germanium tin (GeSn) alloy has recently emerged as a candidate for optoelectronic and high performance CMOS devices because of its tunable direct gap and potential for high electron and hole mobilities. High hole mobility in GeSn channel pMOSFETs has already been demonstrated [1, 2]. However, GeSn as channel for nMOSFETs has not yet been explored. In this work we perform detailed theoretical analysis to gauge the benefits of GeSn channel over Ge for nMOSFETs. Our analysis predicts GeSn nMOSFETs to outperform Ge. GeSn n-channel devices have been successfully fabricated and factors limiting its performance.