Suspended single-crystalline oxide structures on silicon through wet-etch techniques: Effects of oxygen vacancies and dislocations on etch rates

Abstract

Wet-etch techniques to realize suspended microscale structures of single-crystalline SrTiO3 and BaTiO3 grown on Si are explored. The authors examine the effects of oxygen vacancies and dislocations on etch rates. Both oxygen vacancies and dislocations enhance etching, yielding rates that are sufficiently high to enable conventional photoresist to serve as a mask layer. Suspended bridge structures are realized by etching the underlying Si substrate using a potassium hydroxide solution. The ability to realize suspended microscale structures using wet-etch techniques that are compatible with standard semiconductor device processing opens a pathway to integrate multifunctional oxides in microelectromechanical systems.