N-polar GaN/sapphire for mm-wave Power Electronics

Transphorm as the lead contractor will develop N-polar GaN on sapphire on 150mm Sapphire substrates. In phase 1 of the program the effort will focus on establishing the epitaxial layer growth parameters to minimize cost while maintaining epitaxial material quality to achieve the device performance of CW power density of 5W/mm with a peak PAE of 25% at 94GHz. A contact resistance, RC, < 0.1 OĘmm will be demonstrated. In the Option program the effort will focus on developing via hole technology for Sapphire substrates with minimum damage to the active GaN epi. The via-hole process yield will be established. The device yield that meet the metrics of the program will also be studied and limiting factors established. An operating temperature less than 200C at a Pout of 5 W/mm at 94GHz will be demonstrated. Devices will be delivered to the Government for evaluation after both the base and option programs. Within this program the market acceptance of N-polar HEMTs will also be studied and early adopters established.