Thermal characterization of GaN heteroepitaxies using ultraviolet transient thermoreflectance*

Abstract

Thermal transport properties of GaN heteroepitaxial structures are of critical importance for the thermal management of high-power GaN electronic and optoelectronic devices. Ultraviolet (UV) lasers are employed to directly heat and sense the GaN epilayers in the transient thermoreflectance (TTR) measurement, obtaining important thermal transport properties in different GaN heterostructures, which include a diamond thin film heat spreader grown on GaN. The UV TTR technique enables rapid and non-contact thermal characterization for GaN wafers.