| 摘要 |
PURPOSE:To form a tunnel insulating film and an impurity region for a drain through self-alignment by few mask processes by forming a silicon oxynitride film to the surface of a silicon base body in the vicinity of a boundary between first and second silicon nitride film patterns through thermal oxidation treatment in an atmosphere containing steam. CONSTITUTION:The first silicon nitride film pattern 13 and the second silicon film pattern 15 partially superposed on the end section of the pattern 13 through a silicon dioxide film 14 are formed on a silicon base body 11, and the silicon oxynitride film 17 is formed on the surface of the base body 11 in the vicinity of the boundary between the patterns 13, 15 through thermal oxidation treatment in the atmosphere containing steam. The pattern 15 is removed selectively, an n<+> region for the drain is formed in the base body 11 immediately under the film 17 while using the residual pattern 13 as a mask, a floating gate electrode 121 is formed on the film 17, and the film 17 is made function as the tunnel insulating film. The density of integration can be increased because the film 17 and the n<+> type region 19 under the film 17 are formed in a self-alignment manner. |
