Metal bevel process for multi-level metal semiconductor applications
US4425183A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1983 |
| Grant date | Jan 10, 1984 |
| Priority date | — |
| Expiry date | Aug 8, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/978
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A process for beveling the sharp corners on an integrated circuit metal layer, which corners were created by commonly practiced masking and etching steps. In one form, the photoresist mask used to etch the lower level metal pattern is retained on the wafer as during the beveling operation. With a positive photoresist and an aluminum alloy metal lower level layer, an etch with an alkaline photoresist solvent will isotropically remove both photoresist and metal, but at a controlled difference in rate. Beveling of the metal corners suppresses the reentry effect otherwise encountered when subsequent dielectric materials are deposited over the lower level metal layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.