Method of forming a dram cell having a ring-type stacked capacitor
US5429979A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 1994 |
| Grant date | Jul 4, 1995 |
| Priority date | — |
| Expiry date | Jul 13, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B12/033
Abstract
A new method for fabricating a storage capacitor, on a dynamic random access memory (DRAM) cell, having a ring-type sidewall was accomplished. The method involves opening the self-aligned node contact to the source/drain area of the field effect transistor and forming the bottom capacitor electrode. The same photoresist mask used to open the self-aligned node contact is later used to mask and partially etch the polysilicon bottom capacitor electrode to form the ring-type sidewall on the bottom electrode. The storage capacitor is then completed by forming a thin capacitor dielectric and depositing the top electrode. The method provides a simple process that increases the capacitance of the storage capacitor by about 40 percent while not adversely affecting the leakage current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.