Process and apparatus for full wafer deposition

Abstract

A process and apparatus is described for depositing a layer of material over the entire frontside surface of a semiconductor wafer without leaving residues on the backside of said wafer. A semiconductor wafer is placed on the surface of a first wafer support without contacting the frontside surface of the wafer to thereby permit access by deposition materials to the entire frontside surface of the wafer, and then a layer of material is deposited on the entire frontside surface of the semiconductor wafer. To remove any deposits formed on the backside of the wafer during such a deposition, the coated wafer is then placed generally coaxially on the surface of a generally circular second wafer support which will permit access to the outermost portions of the backside of the wafer. In one embodiment the second wafer support is provided with an annular groove coaxially formed in the surface of the second wafer support which faces the backside of the wafer. This annular groove has an outer diameter larger than the diameter of the wafer and an inner diameter smaller than the outer diameter of that portion of the backside of the wafer not containing deposits thereon from the deposition step, so that all of the backside surface containing such depositions is exposed by the groove. The wafer is then etched to remove from the backside any materials deposited thereon during the deposition step, by permitting etchant materials to contact such backside deposits through the annular groove formed in the second wafer support.

Dependencies are inferred from the claim text.