Thermal Analysis of GaN/SiC-on-Si Assemblies: Effect of Bump Pitch and Thickness of SiC Layer

The ever-increasing requirements for high device performance and compact size drive the communications industry to lookfor new materials, technologies, and integration concepts. This simulation-based study investigates the thermal properties of a compact, heterogeneously integrated gallium nitride on silicon carbide (GaN-on-SiC) and silicon (Si) assembly. Thermal simulations and parametric studies are used to determine how the heat spreading and temperature levels in the lateral and vertical directions are affected by the thickness of the SiC layer and the distribution of the thermal interconnects. Results show that a SiC layer thinned down to 100 µm shows more pronounced differences in its thermal characteristics compared to thicker ones, especially in terms of its backside heating. Aspects related to practical implementations are also considered.