Patent ID: 6958255

Claim:
The method of fabricating a microfabricated ultrasonic transducer comprising the steps of: selecting a silicon carrier wafer; selecting a silicon-on-insulator wafer having a thin silicon layer supported on an oxide layer; thermally oxidizing either the silicon wafer or the silicon layer of the silicon-on-insulator wafer to form a silicon oxide layer of predetermined thickness; applying a mask having openings of predetermined size and shape, to expose areas of the oxide layer; etching away the oxide at the exposed openings to define oxide walls; bonding the two wafers with the thin silicon layer facing the silicon carrier wafer and spaced therefrom by the oxide layer whereby cells are formed; and removing the wafer and oxide layer of the silicon-on-oxide-on insulator wafer leaving the thin silicon membrane supported spaced from the silicon carrier wafer by the silicon oxide.