GaN Power Devices for Automotive Applications

Abstract

In this paper, we discuss requirements of power devices for automotive applications, especially hybrid vehicles and the development of GaN power devices. Requirements of automotive applications for novel power devices are high breakdown voltage (~1.5kV), low on-resistance (~1mΩcm 2 ) and normally- off operation. Several types of GaN based power devices and next subjects of the developments are reviewed. All the results of previous works for GaN power devices are really promising to realize high performance and small size inverters for future automobiles. required in the future due to higher motor power and protection against surge voltage. Moreover, low on resistance of the power devices and high temperature operation above 200°C are also required to simplify the cooling system of the inverter. The following performances for the automotive applications are expected to next generation power devices. The breakdown voltage and on-resistance are about 1.5kV and 1mΩ·cm 2 , respectively. Normally-off operation (enhancement mode operation) is also required for fail safe point of view. These requirements with the high temperature operation are very hard for Si-besed power devices. Therefore, wide- bandgap semiconductors, such as SiC and GaN, have much attention as novel power devices which breakthrough the Si limit.