Chip Temperature Influence on Characteristics of MISFET Hydrogen Sensors

The influence of chip temperature on the hydrogen sensitivity of the metal-insulator-semiconductor field-effect transistor (MISFET) with structure Pd-Ta2O5-SiO2-Si was experimentally investigated. MISFET sensing elements were fabricated on single silicon chip together with (p-n)-junction temperature sensor and heater-resistor. There were measured the hydrogen responses of the MISFET threshold voltage for room and higher chip temperatures. The threshold voltage VT as a function of hydrogen concentration C was determined for different temperatures T. The models of hydrogen and temperature sensitivities based on the experimental dependencies of VT (C,T) are presented in this work.