A comparison of MISiC Schottky-diode hydrogen sensors made by NO, N₂O, or NH₃nitridations

MISiC Schottky-diode hydrogen sensors with gate insulator grown in three different nitridation gases (nitric oxide (NO), N2O, and NH3) are fabricated. Steady-state and transien-t-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. This paper 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 a significant response even at a low H2concentration of 48-ppm H2in N2, indicating a potential application for detecting hydrogen leakage at high temperature. Moreover, the three nitrided samples respond faster than the control sample. At 300°C, the response times of the N2O, NO, and NH3-nitrided sample to the 48-ppm H2in N2are 11, 11, and 37 s, respectively, as compared to 65 s for the control sample without the gate insulator.