Electrode structure of memory capacitor
US7999350B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 2008 |
| Grant date | Aug 16, 2011 |
| Priority date | — |
| Expiry date | Mar 3, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D1/716
Abstract
After a fabrication process intended to miniaturize semiconductor devices, a surface area of a stack capacitor in a random access memory (RAM) is significantly reduced and capacity thereof is thus decreased, which in turn causes the capacitor not able to function properly. The present invention provides a composite lower electrode structure consisting of an exterior annular pipe and a central pillar having concave-convex surfaces to increase a surface area of the capacitor within a limited memory cell so as to enhance the capacity. To reinforce intensity of a structure of the capacitor, the exterior annular pipe has an elliptic radial cross section and a thicker thickness along a short axis direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.