Defect density reduction of the Al2O3/GaAs(001) interface by using H2S molecular beam passivation

Abstract

The integration of higher carrier mobility materials to increase drive current capability in the next CMOS generations is required for device scaling. But a fundamental issue regarding the introduction of high-mobility III-V in CMOS is the electrical passivation of the interface with the high-kappa gate dielectric. In this work, we show that in situ H2S surface treatment on GaAs(001) leads to a stable and reorganized oxide/III-V interface. The exposition of the GaAs surface is monitored in situ by RHEED and the interface is characterized by XPS analyses. Finally, MOS capacitors are fabricated to extract interface state density over the band gap. These results highlight a promising re-interest in chalcogenide passivation of III-V surfaces for CMOS applications. (C) 2011 Elsevier B.V. All rights reserved.