A GaN Power Integration Platform Based on Engineered Bulk Si Substrate with Eliminated Crosstalk between High-Side and Low-Side HEMTs

A novel GaN power IC platform on engineered bulk Si (EBUS) substrate is demonstrated for monolithic integration of 200-V high-side and low-side p-GaN HEMTs of a half-bridge circuit. The engineered substrate features a P+-N-doping profile realized by P-type implantation into an N-type (111) Si wafer. The P+ Si layer is then split into P+ islands using deep trenches and are effectively isolated through back-to-back PN junctions. The P+ island provides a local electrical substrate for the overlaying GaN HEMT, while all GaN HEMTs share the same bulk Si wafer; such configuration enables monolithic GaN power integration with eliminated crosstalk associated with conventional bulk Si that serves as a common electrical substrate.