Trench capacitor cells for a dram having single monocrystalline capacitor electrode
US5555520A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1994 |
| Grant date | Sep 10, 1996 |
| Priority date | — |
| Expiry date | Dec 2, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D1/665
Abstract
The present structure is characterized by the electrode of a trench capacitor of a DRAM and a periphery thereof. A trench is formed adjacent to an N type region in a substrate. An insulating film is formed on the side wall of this trench and only a part of the insulating film around the upper portion of the trench is removed, forming a window. An N type polycrystalline silicon film of a lower capacitor electrode is formed over a region from the bottom of the trench to below the window, and a capacitor insulating film is formed on this polycrystalline silicon film. A polycrystalline silicon film which becomes a first upper capacitor electrode is formed on the capacitor insulating film, filling the trench up to the lower edge of the window. A monocrystalline silicon film which becomes a second upper capacitor electrode is formed on the latter polycrystalline silicon film in such a way as to contact an N type region, filling the upper portion of the trench. An insulating film similar to a gate insulating film on the substrate is formed on the monocrystalline silicon film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.