Effects of gate-insulator nitridation gas on MISiC Schottky-diode hydrogen sensors

Abstract

MISiC Schottky-diode hydrogen sensors with gate insulator grown in three different nitridation gases (NO, N 2O and NH 3) are fabricated. Steady-state and transient-response measurements are carried out at different temperatures and hydrogen concentrations using a computer-controlled measurement system. Experimental results show that these nitrided sensors have high sensitivity and can give a rapid and stable response over a wide range of temperature. The study also finds that N 2O provides the fastest insulator growth with good insulator quality, and hence the highest sensitivity among the three nitrided samples. The N 2O-nitrided sensor can give significant response even at a low H 2 concentration of 48-ppm H 2 in N 2, indicating potential applications for detecting hydrogen leakage at high temperature. The response times of the three nitrided samples are also shorter than that of the control sample. At 300 °C, the response time of the N 2O-nitrided sample to 48-ppm H 2 in N 2 is 11 s, while that of the control sample is 65 s. © 2005 IEEE.