Semiconductor device substrate and method of manufacturing semiconductor device substrate

Abstract

A method of manufacturing a semiconductor device substrate includes forming a mask layer pattern on a semiconductor layer insulated from a surface of a semiconductor substrate by an electrically insulating layer, etching the semiconductor layer according to the pattern of the mask layer to form a trench leading to the insulating layer, etching a protective layer on the semiconductor substrate having a thickness less than the thickness of the insulating layer to form a sidewall protective film which covers a side surface of the trench, etching the insulating layer from a bottom surface of the trench to the semiconductor substrate; and growing a single-crystalline layer from the surface of the semiconductor substrate exposed as a result of etching the insulating layer.

Dependencies are inferred from the claim text.