| 摘要 |
PURPOSE:To contrive to enhance controllability of size of polycrystalline Si layers of a semiconductor device by a method wherein after ion implantation is performed to the source and drain regions, the whole surface is oxidized at first, and after the generated oxide film is etched, shallow diffusion layers are formed by self alignment. CONSTITUTION:After formation of a gate film, deposition of polycrystalline Si, formation of an Si oxide film, and formation of an Si nitride film, etching of the source and drain regions is performed, and the source and drain are formed by self alignment. After then, in the process to form the shallow diffusion layers, oxidation of the whole surface is performed at first. At this time, because the rate of oxidation of the polycrystalline Si layer is higher than that of the Si layer, an oxide film thicker than that of the Si layer is formed on the polycrystalline Si layer. When the oxide film is etched after then, an ion implantation practicable N<-> type or P<-> type region is formed between the source and drain regions and the channel region owing to the difference between thickness of the oxide film formed on the surface of the polycrystalline Si layer and the oxide film formed on the surface of the Si layer, and the shallow diffusion layers can be formed by self alignment by performing ion implantation into the regions thereof. |
