900 V/200 A SiC Schottky Diode fabrication on 150 mm substrates in a high-volume Si foundry for automotive traction inverters

Reducing the size, weight, and increasing the efficiency of electric vehicle traction power inverters requires the development of novel high-voltage, high current silicon carbide high-speed rectifiers, since the existing silicon technology is severely limited in terms of operating temperature, frequency and energy efficiency. However, the non-optimized device and manufacturing technology currently used for silicon carbide power diode fabrication results in higher energy losses and a non-competitive price point with respect to silicon, which is the major roadblock that must be overcome to gain entry into the cost-sensitive automotive market. Novel device and process technology in combination with the use of a high-volume manufacturing strategy on large diameter silicon carbide wafers is proposed in this proposed program for achieving near-theoretical device performance on high-current power Schottky rectifiers. The proposed device and manufacturing strategies will drastically reduce the manufacturing costs for silicon carbide Schottky diodes, making them cost-competitive with the existing silicon technology. Phase I will be focused on developing and optimizing the device and layout designs necessary to scale up the rated current of the silicon carbide Schottky rectifiers to levels necessary for automotive traction drive Inverters. A major task would involve transferring the process technology to a large-scale, high-volume foundry identified in the proposal. A systematic method to individually qualify specific process steps at the remote foundry will be devised. A pilot wafer lot will be implemented at the large-volume foundry and the device performance will be benchmarked against the current state-of-the-art in silicon carbide power device technology. Electric vehicle power electronics manufacturers such as 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 countrys 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.