| 摘要 |
PURPOSE:To remove anisotropic etching, controllability of which is difficult, to simplify a process and to improve reliability by forming a high melting-point metallic silicide layer onto the surface of an element forming region, using an silicon nitride film coating only a polycrystalline silicon film selectively shaped as a mask. CONSTITUTION:A gate insulating film 3 is formed onto the surface of an element forming region shaped to one main surface of a P-type silicon substrate 1. A polycrystalline silicon film 4 is formed selectively onto the film 3, and an silicon nitride film 5 is shaped only onto the surface of the film 4 through a method of thermal nitridation. A polycrystalline silicon film 6 as a control gate electrode is formed choicely onto the film 5. The gate insulating film 3 is removed through etching, employing the silicon nitride film 5 as a mask to expose the surface of the element forming region. A titanium film is deposited onto the whole surface through a sputtering method, and a titanium silicide film 8 is shaped through heat treatment. An unreacted titanium film 7 is gotten rid of. A polycrystalline silicon film 4 is formed and used as a floating gate electrode, and an N-type diffusion region 9 is shaped.
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