GaN monolithic inverter IC using normally-off gate injection transistors with planar isolation on Si substrate

We present a GaN monolithic inverter IC on Si substrate and successful motor-drive by it for the first time. Taking advantages of the bi-directional operation free from the forward voltage off-set, the inverter can be operated just by the integrated six GaN-based normally-off gate injection transistors (GITs) without any external fast recovery diodes (FRDs) to flow the fly-wheel current. The IC enables the efficiency as high as 93% at low power operation where so far that of conventional Si-based inverters has remained lower value owing to the forward voltage off-set. The key processing technology is the newly introduced planar isolation using Fe ion implantation which fully isolates the GaN-based lateral devices each other.