Analysis of Heat Dissipation of Nanocrystalline Diamond Capping Layers for GaN HEMTs Applications

The routes and mechanism of heat dissipation of nanocrystalline diamond capping layers for GaN HEMTs applications is systematically investigated by using three dimensional simulations with the finite element method. The distribution of heat for nanocrystalline diamond capping layers device is performed and those results demonstrate the path and mechanism of heat transfer for nanocrystalline diamond capped devices. Meanwhile, the effects of nanocrystalline diamond capping layers structures on the thermal performance of GaN HEMTs are investigated in detail based on temperature distribution around heat sources, and those results indicate geometric parameters of nanocrystalline diamond capping layers have crucial importance influence on heat dissipation, especially the distance between gate to nanocrystalline diamond. In addition, the analysis of temperature gradient illustrates the effect of geometric parameters on junction temperature, and highlight that nanocrystalline diamond capping layers provide a high thermal conductivity path for GaN devices.