Selective Growth of Diamond in Thermal Vias for GaN HEMTs

Abstract

GaN on SiC technology has offered tremendous benefits over existing GaAs-based RF technologies. The high breakdown voltage and current handling capability of GaN HEMTs enable a 10x increase in RF power over conventional GaAs- based devices for the same device size. These benefits translate to dramatically improved performance for military and commercial communications, radar and high-power RF systems. However, despite the high thermal conductivity materials and optimized epitaxial profiles already being used, additional improvement of MMIC performance is limited by thermal constraints. Substrate and near channel thermal resistance is a key thermal bottleneck limiting device compaction and junction temperature reduction. NGAS will report on revolutionary methods being developed to directly integrate high quality, high thermal conductivity diamond materials with more than 4x greater thermal conductivity over existing state-of-the-art GaN on SiC HEMT technology. Reducing temperature in the device channel and surrounding regions is critical for reliable operation, supporting additional device compaction and improving circuit performance.