A Comparison of MISiC Schottky-Diode Hydrogen Sensors Made by NO,$hboxN_2hboxO$, or$hboxNH_3$Nitridations

MISiC Schottky-diode hydrogen sensors with gate insulator grown in three different nitridation gases (nitric oxide (NO), N
₂
O, 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. This paper also finds that N
₂
O provides the fastest insulator growth with good insulator quality and hence the highest sensitivity among the three nitrided samples. The N
₂
O-nitrided sensor can give a significant response even at a low H
₂
concentration of 48-ppm H
₂
in N
₂
, indicating a potential application for detecting hydrogen leakage at high temperature. Moreover, the three nitrided samples respond faster than the control sample. At 300 degC, the response times of the N
₂
O, NO, and NH
₃
-nitrided sample to the 48-ppm H
₂
in N
₂
are 11, 11, and 37 s, respectively, as compared to 65 s for the control sample without the gate insulator