Depleted semi-insulating silicon/silicon material formed by wafer bonding

Wafer bonding has been used to manufacture a silicon material intended as substrate for high-frequency applications. The space charge regions surrounding the bonded silicon/silicon interface deplete the silicon, thereby causing semi-insulating behavior at high frequencies. The material has been characterized electrically for frequencies up to 40 GHz using metal transmission lines on its surface. The results show that transmission lines made on these materials show low losses when signals are transmitted along them. These results have been compared to measurements using similar transmission lines on bulk silicon wafers of different resistivities, on SIMOX wafers, and on quartz.