Simulation study of reduced self-heating in β-Ga2O3 MOSFET on a nano-crystalline diamond substrate

We propose nano-crystalline diamond (NCD) as a heteroepitaxial substrate for beta-gallium oxide (beta-Ga2O3), and investigate self-heating effect in beta-Ga2O3 MOSFET on the NCD compared with a native Ga2O3 and other alternative substrate (SiC) using physics-based TCAD simulation. The NCD substrate with high thermal conductivity reduces a lattice temperature of beta-Ga2O3 and thus mitigates drain current degradation. Furthermore, the benefits become more pronounced with device scaling. These results suggest that the low-cost NCD can be a promising heteroepitaxial substrate for beta-Ga2O3 devices applications.