Evaluaation of alternative High-Temperature high-Field Dielectrics for SiC Devices

Silicon Carbide is exceptionally well suited for high temperature, high-power electronics. These electronics would be ideal for high-temperature applications for electric combat vehicles, including vehicle propulsion, active protection, electric gun and turret control. Therefore, silicon carbide has been identified as a critical electronic technology for use in future armored vehicles. To fully enable the capabilities of silicon carbide electronic devices, a high-temperature high-field dielectric must be developed. Alternative dielectric materials for use on SiC merit thorough investigation, however, silicon dioxide should not be dismissed as a high-temperature high-field dielectric. There are several potential dielectric materials of interest, including A1N and various combinations of silicon, oxygen and nitride. It is proposed that these alternative dielectrics be evaluated for use as high-temperature, high-field gate dielectrics or field passivation. In addition, we propose to look at three materials with extremely high dielectric constants for this application. This effort will include producing metal-insulator-serniconductor (MIS) capacitors in SiC to evaluate which dielectrics show superior applicability for device operation at 350¿C. Dielectrics to be evaluated include silicon oxynitride, AlN, silicon nitride, oxide-nitride-oxide (ONO) layers, thermally grown silicon dioxide, deposited silicon dioxide, A1O:N, TiO(2), Ta(2)O(5) and (Ba,Sr)TiO(3). BENEFITS: High power silicon carbide devices which operate at high temperatures are required for a variety of power conditioning applications for motor control, radar systems, more-electric airplanes, turbine engine actuators, and space-based power systems. These devices would also have a large commercial market in the areas of powey switching and conditioning. These applications require strong reliability at high fields and high temperatures.