Method of making semiconductor wafer

Abstract

Abstract A semiconductor wafer may be made extremely thin, for example, so as to be suitable for use as a solid target of enhanced sensitivity in a vidicon tube, by forming on the marginal portion of one side of a single crystal semiconductor substrate a seeding site which is crystallographically different from the substrate, coating that one side of the substrate with a vapor growth layer of the same conductivity type as the substrate to consist of a polycrystalline region overlying the seeding site and a single crystal region directly overlying the remainder of that side of the substrate, and then removing the semiconductor substrate from the vapor growth layer, as by grinding, to leave a semiconductor wafer of a thickness substantially determined by the thickness of the vapor growth layer and in which cracks that may originate at the edge of wafer, either during grinding or otherwise, are blocked from spreading into the single crystal region at the boundary of the latter with the marginal polycrystalline region. The semiconductor substrate is preferably of a high impurity type so that the concentration of impurity in the single crystal region of the semiconductor wafer produced as aforesaid increases across the thickness of the wafer in the direction toward the surface thereof from which the substrate has been removed.

Inventors

• 👤 Masayoshi Miyazaki

Bibliographic Details