Automotive-qualified SiC DMOSFETs with integrated Schottky Rectifiers

Reducing the size, weight, and increasing the efficiency of automotive traction power inverters requires the development of novel high-voltage, high current silicon carbide power modules, since the existing silicon technology is severely limited in terms of operating temperature, frequency and energy efficiency. However, the legacy silicon based power module technology currently used for silicon carbide power modules results in higher energy losses while still suffering from non-competitive price point with respect to silicon. A disruptive low-cost, high thermal capability, silicon carbide-optimized power module technology is proposed in this program. The proposed device and manufacturing strategies will drastically reduce the manufacturing costs for silicon carbide power modules, thereby fostering their adoption into automotive power electronics systems. Phase I was focused on a proof-of-concept demonstration of the proposed device technology. A major task involved transferring the process technology to a large-scale, high- volume foundry identified in the proposal. Phase II was focused on scaling the voltage and current ratings of the Phase I demonstrated device to 1700 V and up to 250 Amperes, in line with updated requirements from automotive customers. Detailed reliability and robustness investigations pursuant to the industry standards were conducted during Phase II. The innovative automotive-qualified power modules featuring SiC power devices to be developed in this program are targeted for insertion into three-phase traction inverter modules. Electric vehicle power electronics manufacturers such as General Motors, Delphi Automotive and Cummins Power Systems are expected to be direct customers of the proposed silicon carbide devices to be developed in this program. Reducing the weight of the power module, which represents 23% of the total Inverter weight will extend its electric range and/or reduce the size and cost of the battery. Significantly reduced silicon carbide chip-sizes for the same current rating along with low- cost, high-volume manufacturing strategies proposed in this program will help meet the aggressive power electronics targets set for the electric vehicle industry by the DOE for the year 2022. This in turn will enhance the country’s energy security by reducing dependence on foreign oil, save money by cutting fuel costs for American families and businesses, and result in a cleaner environment by reducing harmful CO2 emissions from gas-powered vehicles.