| 摘要 |
<p>PURPOSE:To provide a MOS transistor by implanting ions into a source region with a polysilicon gate as a mask, thermally diffusing the ions to form a lightly doped tub, carrying out ion implantation with a CVD film applied to the side wall of a gate, and forming source and drain regions through annealing. CONSTITUTION:Field oxide 2, gate oxide 3, and a polysilicon gate 4 are formed on a P<-> silicon substrate 1. After a photoresist mask is applied to the substrate, ions are implanted into a source region and thermally diffused sideways to form an n<-> tub 5. A CVD film is formed to provide a side spacer 6, and there are formed a p<+> drain 7a, a p<+> source 7b, and an n<+> source contact layer 8 by ion implantation through an opening and heat treatment. Then, a CVD oxide film 6, aluminum interconnections, and a protective film 11 are provided. Since the edges of the implanted layer fall short by the width of the spacer 6 in this structure, greater room for diffusion of source and drain is provided so that the resistance to punchthrough is ensured easily.</p> |
