Method of making semiconductor memory elements
US5231044A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 14, 1992 |
| Grant date | Jul 27, 1993 |
| Priority date | — |
| Expiry date | Sep 14, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B12/318
Abstract
A method of making a semiconductor memory element such as in dynamic random access memories including forming a transistor on a semiconductor substrate, forming a polysilicon film, a metal silicide film and an oxide film, in this order, over the resultant entire exposed surface so as to form a bit line at the bit line contact, forming another oxide film over the resultant entire exposed surface and forming side wall spacers and a capacitor contact, depositing a first doped polysilicon film over the resultant entire exposed surface, and forming a first smoothing oxide film over the first doped polysilicon film. Over the resultant entire exposed surface, a nitride film is formed which has a thickness larger than that of the first doped polysilicon film by two times or more. A second smoothing oxide film is formed over the nitride film. The nitride film is etched using the smoothing oxide films as a mask. The method also includes depositing a second polysilicon film for a storage node and a third oxide film over the resultant entire exposed surface, etching the second doped polysilicon film using the first, second and third smoothing oxide films as a mask, forming a storage node, and …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.