Multilayered substrate obtained via wafer bonding for power applications

A multi-layer semiconductor device utilizes the good thermal and electrical properties of a polycrystalline substrate with the electrical properties of single crystal film transferred via wafer bonding. The device structure includes a polycrystalline, e.g., silicon carbide substrate, which was polished. A planarization layer of silicon is formed on the surface, followed by chemical mechanical polishing. The substrate is then bonded to either a bulk silicon wafer or a silicon-on-insulator (SOI) wafer. The silicon (SOI) wafer is thinned to the desired thickness.