Patent ID: 8278725

Claim:
A micromechanical structure comprising: a silicon-on-insulator (SOI) substrate; a micromechanical element comprising wide bandgap material formed directly on the substrate; and an undercut formed underneath a released portion of the micromechanical element; the undercut being in the form of a recess formed in an inherent Si overlayer of the SOI substrate; wherein a thickness of the Si overlayer of the SOI substrate is chosen for controlling growth-induced stress in the micromechanical element, for in turn controlling a stress in the released portion of the micromechanical element; and wherein the wide band gap material comprises one or more materials selected from a group consisting of ZnO, Zn(Mg)O, Zn(Cd)O, ZnS, GaN, AIN, AlGaN, InGaN, InN, polycrystalline diamond and nanocrystalline diamond.