Pd/Oxide/InGaP MOS Schottky Hydrogen Sensor with Native Thin Oxide

Abstract

Liquid phase deposition (LPD) grown InGaP native oxide near room temperature (~60oC) is demonstrated and investigated for the first time. A high oxidation rate (~80nm/hr) is obtained and checked by SEM and AES. The oxide is determined to be composed of InPO4 and Ga2O3 which are analyzed by the results of XPS measurement. Due to the presence of excellent quality of InGaP native oxide, high hydrogen (H2) sensitivity in output current of Pd/oxide/InGaP MOS Schottky diode is observed. Under the applied voltage of -1V and 50ppm H2/air, a high sensitivity of 1090 is obtained. In addition, an obvious variation of output current and a short response time due to the exposure to different H2 concentration are also achieved.