Capacitance response characteristics of hydrogen sensor with tantalum oxide dielectric layer

摘要

Sensors with silicon substrates are limited in their application at higher temperatures than 250 degrees C due to the small band gap energy in silicon. In this study, a hydrogen gas sensor with metal-oxide-semiconductor (MOS) structure capable of operating at high temperatures above 300 degrees C is investigated. The sensor consists of a tantalum oxide layer on a SiC substrate with the large band gap energy for effectively detecting hydrogen gas. The tantalum oxide is formed by rapidly oxidizing the deposited Ta at 900 degrees C. To estimate response characteristics of the sensor, variations in capacitance and current-voltage characteristics after exposure to different hydrogen concentrations up to 2000 ppm were examined at temperatures ranging from room temperature to 600 degrees C. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.