COMPARISON OF HIGH TEMPERATURE MRISiC BASED GAS SENSORS WITH DIFFERENT SENSING LAYERS

Metal Reactive Insulator Silicon Carbide (MRISiC) Devices with different reactive insulator layers of Ga203, TiOz, and WOs have been fabricated and their hydrogen gas sensing performance has been investigated. Responses of devices with different reactive insulator layers have been compared in terms of barrier height, operating temperature range, series resistance, time constants and turn on voltage, all of which are modified by changing the reactive insulator layer. It is shown that exposure to different gas concentrations results in changes in carrier concentration and in barrier height, which results in a change in the forward bias voltage. Voltage shifts as large as 1 V have been observed. In addition, parameters have been extracted from Current-Voltage (I-V) measurements, which have shown changes in barrier height as large as 50 meV for Hz concentrations of 1%.