| 摘要 |
PURPOSE:To obtain a dynamic semiconductor-memory having a higher integrating density by forming the capacity of polycrystalline Si, n type region, insulating film and gate which constitute a semiconductor memory according to self alignment. CONSTITUTION:A field-insulating film 2 is formed on the ends of a p type Si substrate 1, and the surface of the substrate 1 surrounded by the film 2 is coated with a n type Si region 3. Then, an insulating film 4 of SiO2 or Si3N4 is provided on the film 2 and the region 3, and all covered with polycrystalline Si layers 5-1 and 5-2 except for the gate forming region, before being treated on heating to change the surface layer into an oxide film 6. After that, in the gate forming region an opening 7 Is made reaching the substrate 1, and treated on heating to produce an gate insulating film 8 on the exposed surface of the substrate 1 and the side wall of the opening 7. On doing this, the region 3 slightly invades and substrate 1. However, it is utterly negligible. Then, the film 8 is coated with a gate electrode 9 of Mo and polycrystalline Si, and the whole surface is covered with an interlayer insulating film 10, in which an opening 12 is made, and the whole surface is coated with an electrode 11 to be a bit wire which contacts with the layer 5-1. |
