Silicon-on-insulator (SOI) is a rapidly evolving technology. In a few years, it has evolved from materials research to high-leverage integrated circuits applications. SOI MOSFETs have several unique properties which make SOI technology very attractive for integration in the deep-submicron regime. In addition, SOI devices are inherently much more resistant to ionizing particles than bulk transistors. SOI devices are also the building blocks of three-dimensional ICs, which offer interesting possibilities in the field of smart sensors with on-chip signal processing.