Surface micromachined freestanding ZnO microbridge and cantilever structures on Si(111) substrates

In this study, the authors report on the fabrication processes to realize the freestanding ZnO micromechanical structures on Si(111) substrates. Arrays of freestanding cantilevers and microbridges have been fabricated using a combination of dry etching techniques. The mechanical properties of the released ZnO structures are characterized by micro-Raman spectroscopy. The residual stress in these freestanding micromechanical structures is determined from the E2(2) phonon peak shift. Such a method to realize the freestanding structures on Si platform would be useful for the fabrication of ZnO-based microelectromechanical systems and sensors.