| 摘要 |
PURPOSE:To thicken a tunnel insulating film, and to hold memory informations excellently by opposing a silicon substrate formed to a projecting shape and a floating gate through the tunnel insulating film and opposing the floating gate so as to coat the end section of a projecting type silicon substrate. CONSTITUTION:A mask material 12 for forming a projecting section is left on a P type silicon substrate 11 in a desired shape, the silicon substrate 11 is removed, and the projecting section is formed. An oxide film 13 is buried to the formed projecting section so as to coincide with the surface of the silicon substrate 11. A mask material 14 coating sections except a region containing the projecting section of the silicon substrate 11 and one part of the buried oxide film 13 is left, an N<+> layer 15 in the silicon substrate 11 is formed and one part of the oxide film 13 is removed, and the surface of the oxide film is retreated from the surface of the projecting section of the silicon substrate 11. A tunnel oxide film 16 is grown to the projecting section of the silicon substrate 11, and a floating gate 17 consisting of polycrystalline silicon is formed. |
