Record-Low Thermal Boundary Resistance between Diamond and GaN-on-SiC for Enabling Radiofrequency Device Cooling
Mohamadali Malakoutian, D. Field, Nicholas Hines, Shubhra S. Pasayat, Samuel Graham, Martin Kuball, Srabanti Chowdhury
Abstract
/GaN interface, which is the closest to theoretical prediction to date. The diamond was integrated within ∼1 nm of the GaN channel layer without degrading the channel's electrical behavior. Furthermore, we successfully minimized the residual stress in the diamond layer, enabling more isotropic polycrystalline diamond growth on GaN with thicknesses >2 μm and a ∼1.9 μm lateral grain size. More isotropic grains can spread the heat in both vertical and lateral directions efficiently. Using transient thermoreflectance, the thermal conductivity of the grains was measured to be 638 ± 48 W/m K, which when combined with the record-low thermal boundary resistance makes it a leading-edge achievement.