| 摘要 |
PURPOSE:To prevent the deterioration in dielectric strength by a method wherein an insulator film is formed on the surface of the side wall of a gate electrode prior to ion implantation. CONSTITUTION:The side wall of the gate electrode 21 is coated with an insulation film 22, and ions are implanted. Since the ions are not implanted to the lower end of the electrode because of the ability of the insulation film to block ion implantation, the gate oxide film is not subjected to damage due to the ions and does not generate the deterioration in strength. The insulation film requires a film thickness whereby ions do not reach both lower ends of the gate electrode. Thereby, the deterioration of the strength of the gate oxide film immediately under both ends of the MOS transistor gate electrode can be prevented, and the effect that the operating lifetime and the reliability of the semiconductor device using said transistor improve becomes remarkable. |
