Impact of volatile organic compound exposure on electrical breakdown in GaN dual channel microcantilevers

Abstract

The impact of volatile organic compound (VOC) exposure on the electrical breakdown of GaN in the inter channel region of dual channel microcantilever heaters has been studied. Exposure to three different VOCs with different latent heats of evaporation resulted in changes in breakdown voltage of varying magnitudes that can be correlated with their latent heats. A physical model has been proposed to explain the observed shift in breakdown voltage upon VOC exposure based on changes in thermal and electrical profiles at the microcantilever apex, which is caused by the molecular interaction and amplified by its unique tapered geometry. The critical breakdown field of the inter channel GaN has been observed to reduce dramatically by almost 50 times compared to that of bulk GaN at room temperature. The inter-channel current rises dramatically at the onset of breakdown induced by VOC exposure, at specific bias voltages corresponding to VOCs, which can be utilized for detecting them with high sensitivity as well as selectivity.