SBIR-STTR Award

4H-silicon carbide power devices are expected to have 3x higher current densities and 200x lower on-resistance, while still operating up to 350 degree C. This is because of an order of magnitude higher breakdown electric field and a 2-3x higher thermal conductivity of 4H-SiC as compared to Si. Recent advances in 4H-SiC crystal quality, low doped epitaxial uniformity, dopant ion implantation, reactive ion etching and high voltage edge termination at Cree presents tremendous opportunity to fabricate high power 4H-siC ACCUFET devices. In this Phase I research, 1000 V, 1 Amp ACCUFETs capable of operating up to 350 degree C. The experimental results from the fabricated devices will then be compared with those obtained in the simulation design and further optimization will be carried out in Phase II of the program. A simulation study of various structures possible with an accumulation mode FET will also be conducted.

Benefits:
A high power, high speed 2H-SiC ACCUFET operating at a high temperature (350 degree C) is expected to play an enabling and vital role in the design of the future concept MEA. The system level benefits include a reduction in flight control system weight and improved reliability; reduction in the size and weight of the environmental control system required to cool PMAD and flight control eletronics; a reduction in engine control system weight and increased reliability and maintainability of stores management system avionics. High temperature devices like the 4H-Sic ACCUFET can be mounted on engines for control, and in electronic warfare or other stores attached to the fuselage or wings of the aircraft. The commercial market segments for these devices include light industrial and utilities including electric vehicles; air conditioning and heat pumps; and, medical equipment like MRI and PET systems.

Silicon carbide power divices are expected to have 3X higher current densities and 200X lower on-resistance, and a 350C operating capability. this is because of an order of magnitude higher bredkown electric field and a 2-3X higher thermal conductivity of SiC as compared to Si. Recent advances in SiC crystal quality, low doped epitaxial uniformity, dopant ion implantation, reactive ion etching and high voltage edge termination at Cree presents tremendous opportunity to fabricate high power SiC ACCUFETs and Schottky diodes. In this program, 700 V, 20 Amp SiC ACCUFETs and Schottky diodes capable of operating up to 350C will be designed and fabricated. The experimental results from the initial lots of fabricated devices will be used to obtain an optimized design for the lowest on-resistance, low leadage, high temperature ACCUFETs. The disign will also include a study of using these critical power circuit components together in a standard H-bridge converter, in which these devices are used in an anti-parallel configuration.

Benefits:
High power, high speed SiC Accufets and Schottky diodes operating at a high temperature (350C) are expected to play an enabling and vital role in the design of the future concept MEA. The system level benefits include a reduction in flight control system weight and improved reliability; recution in the size and weight of the environment control system required to cool PMAD and flight control electronics; a reduction in engine control system weight and incureased reliability and maintainability of stores management system avionics. High temperature modules containing these high performance ACCUFETs and Schottky diodes can be mounted on engines for control, and in electronic warfare or othe stores attached to the fuselage or wings of the aircraft. The commercial market segments for these devices include light industrial and utilities including electric vehicles; air conditioning and heat pumps; and, medical equipment like MRI and PET systems