Ultralow Voltage Operation of ${\rm Al}/{\rm La}_{x}{\rm Ce}_{1-x}{\rm O}_{z}/{\rm 4H\hbox {-}SiC}$ for Oxygen Sensing

A metal-reactive oxide-silicon carbide (SiC) sensor, responding to oxygen gas, was fabricated using a La_xCe_1-xO_z layer deposited between 4H-SiC substrate and Al gate as a function of postdeposition annealing (PDA) of the oxide layer from 400 to 1000°C. Sensitivity of the sensor increased with increasing of the PDA temperature. Current-time and current-gate voltage response was investigated in ultralow voltage regime under a forward bias of 0.3 V to study sensitivity of the sensor. Sensing mechanism of the sensor toward the oxygen gas was proposed and discussed.