Phosphorus oxide gate dielectric for black phosphorus field effect transistors

TL;DR

This paper demonstrates that phosphorus oxide passivation improves the stability and performance of black phosphorus field effect transistors, achieving high room temperature mobility in ambient conditions.

Contribution

It introduces a phosphorus oxide passivation technique for black phosphorus transistors, enhancing stability and mobility compared to previous methods.

Findings

Room temperature mobility of 115 cm²/Vs achieved in ambient conditions

Phosphorus oxide passivation reduces defect density at the bP interface

Enhanced environmental stability of black phosphorus transistors

Abstract

The environmental stability of the layered semiconductor black phosphorus (bP) remains a challenge. Passivation of the bP surface with phosphorus oxide, POx, grown by a reactive ion etch with oxygen plasma is known to improve photoluminescence efficiency of exfoliated bP flakes. We apply phosphorus oxide passivation in the fabrication of bP field effect transistors using a gate stack consisting of a POx layer grown by reactive ion etching followed by atomic layer deposition of Al2O3. We observe room temperature top-gate mobilities of 115 cm2/Vs in ambient conditions, which we attribute to the low defect density of the bP/POx interface.