Semiconductor memory and its manufacturing method

Abstract

Abstract PURPOSE:To obtain large electrostatic capacity with a small substrate area by forming a memory capacitor for a dRAM in multilayer structure as being used in a variable capacitor. CONSTITUTION:When manufacturing a capacitor having multilayer structure of two layers or more consisting of a semiconductor and an insulating film, impurity ions 6 are implanted selectively to the N type semiconductor 7 by using a mask 5 through ion implantation technique, and P<+> layers 8 are formed in the semiconductor. When the ions are implanted several times while changing the energy of the implantation, a plural layer of the P<+> layers are introduced into Si. Only the P<+> layers are removed through selective etching. The surface of the semiconductor is coated with an oxide film 3 by using a thermal oxidation method, etc. When the oxide film is coated with a high conductivity polycrystalline Sig through CVD, a desired capacitor is completed. Accordingly, an area and depth occupying in the surface of a semiconductor layer of the capacitor can be manufactured in small values, and sufficient electrostatic capacity can be provided to the capacitor.

Inventors

• 👤 Masahiro Shigeniwa
• 👤 昌弘 茂庭
• 👤 Masanobu Miyao
• 👤 正信 宮尾
• 👤 Osamu Okura
• 👤 理 大倉
• 👤 Kikuo Kusukawa
• 👤 喜久雄 楠川
• 👤 Yoshio Sakai
• 👤 芳男 酒井
• 👤 Hideo Sunami
• 👤 英夫 角南

Bibliographic Details