Abstract: A multi-gas sensor device for the detection of dissolved hydrocarbon gases in oil-filled electrical equipment. The device comprising a semiconductor substrate, one or more catalytic metal gate-electrodes deposited on the surface of the semiconductor substrate operable for sensing various gases, and an ohmic contact deposited on the surface of the semiconductor substrate. The semiconductor substrate comprises one of GaN, SiC, AlN, InN, AlGaN, InGaN and AlInGaN. A method for sensing gas in an oil-filled reservoir of electrical equipment, comprising providing a sensor device, immersing the sensor device in the oil-filled reservoir, allowing the gases emitted from the oil to interact with the one or more catalytic metal gate-electrodes, altering the gas as it contacts the catalytic metal gate-electrodes and altering the sensitivity of the sensor.

Abstract: A method of processing a semiconductor substrate is provided. The method includes depositing an amorphous hydrogenated carbon film on a semiconductor substrate using a low temperature plasma deposition process and performing at least one high temperature processing step on the semiconductor substrate. The SiC substrate is processed by ion implanting at least one dopant species into at least one selected region of the SiC substrate, depositing a amorphous hydrogenated carbon film on the SiC substrate using a plasma enhanced chemical vapor deposition (PECVD) process, performing at least one high temperature processing step on the SiC substrate and removing the amorphous hydrogenated carbon film after performing the high temperature processing step.

Abstract: A transistor switch for a system operating at high frequencies is provided. The transistor switch comprises a graded channel region between a source region and a drain region, the graded channel region configured for providing a low resistance to mobile negative charge carriers moving from the source region to the drain region, wherein the graded channel comprises at least two doping levels.

Abstract: The invention is directed to a method for optical and electrical isolation between adjacent integrated devices. The method comprises the steps of forming at least one trench through an exposed surface of a semiconductor wafer by removing a portion of the semiconductor wafer material, forming an electrically insulating layer on the sidewalls and the bottom of the at least one trench, filling the at least one trench by conformally depositing an optically isolating material, and planarizing the semiconductor wafer surface by removing the portion of the optically isolating material above the exposed surface of the semiconductor wafer.