Manufacture of semiconductor memory device

Abstract

Abstract PURPOSE:To microminiaturize a semiconductor memory device by regulating a space between a first groove formed in an element region and a second groove shaped in a memory capacitor region by a second mask through the leaving of a side wall. CONSTITUTION:A laminated film consisting of an SiO2 film 22 and an Si3N4 film 23 is formed on a p type silicon substrate 21, and the laminated film is patterned to a predetermined shape to form first masks 241, 242. An SiO2 film 25 is deposited on the whole surface, and left as first masks 251, 252 through the etching of the whole surface. The Si substrate 21 is etched while using the first masks 241, 242 and the second masks 251, 252 as etching-resisting masks to form a first groove 26. An SiO2 film 27 is buried in the first groove 26. Photoresists 281, 282 are shaped, and second grooves 291, 292 are formed while using the photoresists 281, 282 the second masks 251, 252 and the buried SiO2 film 27 as etching-resisting masks. Sections among the second grooves 291, 292 in a memory capacitor region and the first groove 26 in an element isolation region are brought to the state in which the sections are divided by the walls of thin silicon layers self-aligned by the second masks 251, 252.

Inventors

• 👤 Sunao Shibata
• 👤 直 柴田

Bibliographic Details