Manufacture of mos type semiconductor memory device

Abstract

Abstract PURPOSE:To obtain a large memory capacity with a limited area of the device by shaping the memory capacity section composing a MOS semiconductor memory device three-dimensionally. CONSTITUTION:A thick SiO2 film 2 is provided in a nonactive region about a semiconductor substrate and after a thin SiO2 film 9 is applied on an active region surrounded thereby, a PSG or an Si3N4 film 10 is entirely formed thereover. Then, an opening is etched through a part of the active region to expose the substrate 1 in the region 11, where the first polycrystaline Si body 12 containing impurities having a pillar like undersurface and the surface parallel to the substrate 1 is exposed onto the end of a laminated film in the region 11. Once the films 10 and 9 are removed, a gate SiO2 film 31 is applied entirely covering the active region and the surface of the Si body 12. Subsequently, the second polycrystal line Si body 131 containing impurities is provided wrapping the first Si body 12 to form an electrode of a polycrystal line Si on the film 31 exposed thereby increasing the surface area of the memory capacity section.

Inventors

• 👤 Masayoshi Ino

Bibliographic Details