Gates of AlGaN/GaN HEMT for high temperature gas sensing applications

Abstract

The sensing capability of the Pt or Ir based Schottky gate electrodes on AlGaN/GaN heterostructures at elevated temperatures can be improved. It is carried by inserting a thin interlayer of conductive metal oxide between the sensing electrode and the semiconductor barrier layer. High temperature sensing ability of new composite gates is evaluated by detection of hydrogen. We investigate the different absorbing layers and the influence of composition and interfacial oxide layer thickness on sensitivity and response time of gas sensors.