Highly selective etch process for submicron contacts
US6001699A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 23, 1996 |
| Grant date | Dec 14, 1999 |
| Priority date | — |
| Expiry date | Jan 23, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31116
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for forming contacts with vertical sidewalls, high aspect ratios, improved salicide and photoresist etch selectivity at submicron dimensions. In one currently preferred embodiment, an opening is formed in a dual oxide layer by etching the undoped oxide layer at a first rate and then etching the doped oxide layer at a second rate. The etch process is performed in a low density parallel plate reactor. The process parameters of the etch are fixed in ranges which optimize the etch process and allow greater control over the critical dimensions of the opening. For example, the oxide layer is etched at a pressure in the range of approximately 100-300 mTorr and with an etch chemistry having a CHF.sub.3 :CF.sub.4 gas flow ratio in the range of approximately 3:1-1:1, respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.