Separation of silicon wafers by the smart-cut method

Abstract

 Great efforts have been made for many years to develop methods of achieving thin monocrystalline layers of semiconductor material. The Smart-Cut^® process is presented here, a generic process enabling practically any type of monocrystalline layer to be achieved on any type of support. The Smart-Cut^® process is based on proton implantation and wafer bonding. Proton implantation enables delamination of a thin layer from a thick substrate to be achieved whereas the wafer bonding technique enables different multilayer structures to be achieved by transferring the delaminated layer onto a second substrate. The physical mechanisms involved in the delamination process are discussed based on the study of proton-induced microcavity formation during implantation and growth during annealing. It is shown that this industrially economic process is particularly well suited to achieving very high-quality SOI material. Other examples of industrially developed applications of the process are also given.