WHAT KINDS OF SOI WAFERS ARE SUITABLE FOR WHAT MICROMACHINING PURPOSES

Commercially available SOI (silicon-on-insulator) wafers of SIMOX (separation by implanted oxygen), ZMR (zone melting recrystallization) and bonded types are compared from the viewpoint of applications to sensors and actuators (S & A). These are whole-wafer-scale SOIs. Other localized SOI technologies are also discussed. SOI wafers are especially attractive for smart power S & A, as each component is dielectrically isolated. Single-crystal silicon mobile elements, such as diaphragms, cantilevers, bridges, rotors, valves, etc., can be fabricated by the sacrificial layer technique. SIMOX provides the thinnest single-crystal silicon element, which promises the highest natural frequency and the greatest flexibility.