Unified contact plug process for static random access memory (SRAM) having thin film transistors
US5545584A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 1995 |
| Grant date | Aug 13, 1996 |
| Priority date | — |
| Expiry date | Jul 3, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B10/125
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method was achieved for making a static random access memory SRAM by integrating or merging into the SRAM process a unified contact plug process that reduces the number of processing steps and forms low resistance ohmic contacts between N.sup.+ and P.sup.+ polysilicon layers. The plug process utilizes patterned features in the multi-layers of polysilicon and the high selective etching of silicon oxide to polysilicon to form all the contact concurrently, and thereby eliminate the need to etch contacts openings between each polysilicon layer. The unified contact plug method was demonstrate on the SRAM for making the a buried contacts for the node contacts on the SRAM, the bit line contacts and a V.sub.ss contact for the ground plane in the SRAM cell.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.