Manufacture of semiconductor storage device

Abstract

Abstract PURPOSE:To form a capacitance section and a transistor section into a groove through a simple and easy method by burying polysilicon into the groove, shaping the groove in the polysilicon again and burying a word line electrode again. CONSTITUTION:Grooves are shaped through anisotropic etching so as to reach a p<+> substrate, using resists 3 as masks, SiO2 films 5 and Si3N4 films 6 are formed as capacitance insulating films, and polysilicon 7 is buried into the grooves. The grooves 7 are shaped through anisotropic etching, employing the resists 3 and the Si3N4 films 6 as masks, but the depth of the grooves determines the gate length of a transistor. Polysilicon is oxidized, oxide films 8 are formed, the exposed Si3N4 films 6 and the SiO2 films 5 are removed, gate oxide films 9 are grown, word lines 10 are buried into the grooves, and a bit line 13 is wired. n<+> polysilicon is proper as the bit line. An n<+> layer 12 is formed through thermal diffusion from the polysilicon.

Inventors

• 👤 Keimei Mikoshiba
• 👤 御子柴　啓明

Bibliographic Details