| 摘要 |
PURPOSE:To avoid damage to a gate oxide film by having a gate electrode covered with an insulator when source and drain regions are formed by ion implantation with the gate electrode as mask after it is provided on a semiconductor substrate employing a polycrystalline Si and a high-melting-point metal. CONSTITUTION:A thick field oxide film 2 is formed on the periphery of a semiconductor substrate 1 penetrating into the substrate and a thin gate oxide film 3 is applied on the surface of the substrate 1 surrounded thereby. Then, a gate electrode 4 made up of a polycrystalline Si made conductive by containing impurities or a high-melting-point metal is provided in the center of the film 3 and with the electrode as mask, an ion is implanted into a substrate on both sides of the electrode to form source and drain regions. This point, all the exposed surfaces of the electrode 4 is covered with an oxide film 5. This prevents a part of the charge contained in the ion of the impurities to reach the electrode 4 resulting in less charge to be accumulated in the electrode 4 eliminating chances to breaking the film 3. |
