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

MISiC Schottky-diode hydrogen sensors with gate insulator grown in three different nitridation gases (NO, N2O and NH3) are fabricated. Steady-state and transientresponse 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 N2O provides the fastest insulator growth with good insulator quality, and hence the highest sensitivity among the three nitrided samples. The N2O-nitrided sensor can give significant response even at a low H2concentration of 48-ppm H2in N2, 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 N2O-nitrided sample to 48-ppm H2in N2is ll s, while that of the control sample is 65 s.