JPS5773974A - Manufacture of most type semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the disconnection of a wire and to suppress the variation in the threshold voltage by forming a recess on a part of a semiconductor substrate to isolate source and drain regions, forming a gate insulating film on the recess, laminating a polycrystalline Si layer and a nitrided layer on the overall surface, and performing a reactive ion etching. CONSTITUTION:A thick field oxidized film 43 is formed on the periphery of a P type Si substrate 41, ions are injected on an element region 42 surrounded by the film, and an n<+> type layer 44 is formed consequtively thereto by a heat treatment. Subsequently, a resist film 45 is coated on the overall surface, the film 45 is removed corresponding to the gate region, is then etched to form a recess intruded into the substrate 41, and source and drain regions 44a, 44b are formed at both sides. Thereafter, the film 45 is removed, a gate oxidized film 46 is newly covered, and a polycrystalline Si layer 47 and an Si3N4 film 48 are laminated thereon. Then, reactive ion etching is performed to remain at the gate electrode 47 made of the layer 47 only in the recess, and unnecessary layer 47 and the film 48 are removed.