Sensors & Transducers (Sep 2007)

Influence of Pt Gate Electrode Thickness on the Hydrogen Gas Sensing Characteristics of Pt/In2O3/SiC Hetero-Junction Devices

  • S. Kandasamy,
  • W. Gao,
  • A. Holland,
  • W. Wlodarski,
  • T. Katsube

Journal volume & issue
Vol. 83, no. 9
pp. 1549 – 1554

Abstract

Read online

Hetero-junction Pt/In2O3/SiC devices with different Pt thickness (30, 50 and 90nm) were fabricated and their hydrogen gas sensing characteristics have been studied. Pt and In2O3 thin films were deposited by laser ablation. The hydrogen sensitivity was found to increase with decreasing Pt electrode thickness. For devices with Pt thickness of 30 nm, the sensitivity gradually increased with increasing temperature and reached a maximum of 390 mV for 1% hydrogen in air at 530°C. Atomic force microscopy (AFM) analysis revealed a decrease in Pt grain size and surface roughness for increasing Pt thickness. The relationship between the gas sensing performance and the Pt film thickness and surface morphology is discussed.

Keywords