A Study on the Effect of Ion Implant to Wafer Shape and the Ion Implanter to Process the Distorted Thin SiC Wafer

Silicon carbide (SiC) wafers are becoming widely used for making power devices. In order to reduce the wafer cost and the electric power consumed by the SiC power devices, the thickness of SiC wafers are being made thinner and thinner to restrain the R_on (On-state resistance). Ion implantation is an essential process for manufacturing SiC devices. We have found a thinner SiC wafer is more likely to be distorted during manufacturing processes. Processes such as thermal process, film coating and ion implantation can change the shape of the wafer. In this study, the wafer distortion (bow, the deformation of the median surface of a free and unclamped wafer at the center point) induced by ion implantation has been investigated and the ion implanter which can handle the distorted thin SiC wafer is explained.