15 kV High Power Silicon Carbide Diodes

Diode rectifiers are one of the basic building blocks of any power system, ranging from common household appliances to motor controllers to power distribution systems to advanced military weapons and vehicles. Silicon technology for high voltage diodes islimited to ~9 kV. For higher voltage applications, multiple diodes must be used in series, raising the problems of uniform voltage distribution and current balancing. Increasing the blocking voltage of individual devices can alleviate these problems,increase efficiency, reduce cooling requirements and reduce system volume. Silicon carbide (SiC), a wide band-gap semiconductor, offers the potential for electronic devices that operate at higher voltage, higher temperature and higher frequency thansilicon, thereby enabling compact, more efficient power distribution and control. In this SBIR program Extreme Devices, in collaboration with Voltage Multipliers, Inc., proposes to design and fabricate high voltage SiC p-n diodes based upon ExtremeDevices' patented supersonic beam process for producing high quality doped epilayers This process will enable fabrication of the thick, doped high quality epilayers required for high-voltage single-junction diodes. In Phase I, demonstration 15 kV, 1A SiCdiodes will be designed, fabricated and characterized. Phase II will design, fabricate and package larger, higher power devices.High power SiC diodes have enabling advantages over Si diodes, including higher thermal conductivity, higher breakdown voltage,higher temperature operation, lower losses and higher switching frequency. These properties open the door to production of smaller, more powerful and efficient circuitry for both military and commercial power control and distribution.