High-temperature stable MoAl2.7/n-GaAs Schottky diodes with enhanced barrier height

Abstract

High-temperature stable and smooth gate materials are required for self-aligned GaAs metal-semiconductor field effect transistor devices processing. Furthermore, the high Schottky barrier is beneficial to the GaAs digital logic circuits based on the enhancement mode field effect transistors. We report the high-temperature (up to 900 °C) stable MoAl2.7 Schottky contacts to n-GaAs with enhanced barrier heights from 0.67 to 0.98 V and low values of ideality factors after annealing. The surface of annealed contact is lustrous and smooth. The epitaxial AlxGa1−xAs layer, which induces the enhanced barrier height, at the interface of MoAl2.7/n-GaAs contact, has been clearly identified by the high-resolution cross-sectional transmission electron microscopy.