Edge removal of silicon-on-insulator transfer wafer

Abstract

A silicon-on-insulator transfer wafer having a front surface with a circumferential lip around a circular recess is polished. In one version, the circular recess on the front surface of the wafer is masked by filling the recess with spin-on-glass. The front surface of the wafer is exposed to an etchant to preferentially etch away the circumferential lip, while the circular recess is masked by the spin-on-glass. The spin-on glass is removed, and the front surface of the transfer wafer is polished. Other methods of removing the circumferential lip include applying a higher pressure to the circumferential lip in a polishing process, and directing a pressurized fluid jet at the base of the circumferential lip.

Dependencies are inferred from the claim text.