特　　 集 －17－ 特 集 Device Applications Using Bonded SOI Wafers＊

In the semiconductor device, the thick film SOI structure can separate various devices by dielectric isolation and can improve the noise immunity and thermo-tolerance demanded as automotive electronics remarkably. Moreover, it is suitable for integration of the high voltage devices in a high density. In addition, this structure can simplify the wafer processing in the MEMS field and can especially realize a unique sensor.1) On the other hand, the silicon wafer direct bonding technique enables a new structure such as the buried electrode etc. to be formed in the substrate, and can give the semiconductor device a new, additional function. In this paper, some semiconductor devices that we developed by using the feature of SOI structure mentioned above will be described