"Plug-up": A new concept for fabricating SOI MEMS devices

This paper reports a novel process sequence for fabricating micromechanical devices on silicon-on-insulator (SOI) wafers. Among the merits of the described process are its improved immunity to stiction and elimination of conductor metal endurance problems during sacrificial etching in hydrofluoric acid. With this novel process one can controllably embed vacuum cavities within SOI substrates. Further processing of such cavity wafers enables realization of a wide variety of micromechanical devices based on single crystalline silicon or even integrated read-out circuitry.