Patent ID: 6232139
Filing Date: 2001-05-15
Classification: B81B,H03H,Y10S

Abstract:
A process for forming a very thin, crystalline, suspended layer of a first piezoelectric compound semiconductor material comprising:forming a substrate layer of a second piezoelectric compound semiconductor material,then forming a sacrificial layer on the upper surface of the substrate layer by epitaxial deposition of a related compound semiconductor material that is lattice-matched to the second material,then forming by epitaxial deposition a very thin layer of the first material on the upper surface of the sacrificial layer,then creating at least one opening in either the substrate layer or the very thin layer to expose the adjacent surface of the sacrificial layer, the at least one opening being created with a first etchant solution that dissolves the second or first material, respectively, andthen dissolving the sacrificial layer beneath a region of the very thin layer that is to form the suspended portion of the very thin layer with a second etchant that preferentially dissolves the sacrificial layer.