Reliable and Self-Clamped GaN Switch
All electronics, from laptops to electric motors, rely on power electronics to control or convert electrical energy from one form to another for proper operation. They are projected to play an increasingly important role in the delivery of electricity with as much as 80% of electricity passing through power electronics between generation and consumption by 2030. Achieving high power conversion efficiency in power electronics systems requires low-loss power semiconductor switches, but modern silicon-based technology has a number of limitations including high switching and conduction losses, low switching frequency, and poor high-temperature performance. New opportunities for higher efficiency have emerged with the development of devices based on wide bandgap (WBG) power semiconductors such as Gallium Nitride (GaN) and Silicon Carbide (SiC). WBG devices are capable of low-loss operation at high voltages, high frequencies, and high temperatures. Power electronics based on high voltage (>1200V) WBG devices can achieve both higher efficiency and higher gravimetric and volumetric power conversion densities which is beneficial for electric vehicles, data centers, elevators, HVAC, and renewable electric power generation such as solar and wind. GaN has properties that can enable higher performing switching power transistors than silicon and SiC, but GaN-based transistors suffer from reliability issues and have yet to attain the high voltage performance that they can theoretically deliver. Technical and manufacturing improvements in power electronics promise enormous energy efficiency gains throughout the U.S. economy.
Project Innovation + Advantages:
Qromis will develop a new type of gallium nitride (GaN) transistor, called a lateral junction field effect transistor (LJFET) and investigate its reliability compared to other types of transistors, such as SiC junction field effect transistors (JFETs) and GaN-based high electron mobility transistors (HEMTs). Qromis' innovative LJFET design distributes and places the peak electric field away from the surface, eliminating a key point of failure that has plagued GaN HEMT devices and prevented them from achieving widespread use. If successful, this project will deliver a 1.5kV, 10A GaN LJET devices that would be scalable to 100A. The devices will be fabricated on thick, uniform GaN layers deposited on a coefficient of thermal expansion matched 8-inch QST® engineered platform that is compatible with current silicon processing equipment - reducing the cost of the devices. The uniform GaN layers on the large area platform will increase the yield of the devices further decreasing the cost. Finally, the thick GaN will enable the higher voltage standoff and improve the thermal management of the devices.