Protection of aluminum metallization against chemical attack during photoresist development
US5480748A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 1994 |
| Grant date | Jan 2, 1996 |
| Priority date | — |
| Expiry date | Apr 26, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/958
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A conductive layer in a semiconductor device is protected against chemical attack by a photoresist developer by forming a protective film overlying the conductive layer. The protective film is formed using a chemical reaction that occurs through defects in a passivation layer that was previously formed overlying the conductive layer. The chemical reaction substantially occurs at the surface of the conductive layer and chemically converts portions thereof in forming the protective film. Preferably, the conductive layer is aluminum or an alloy thereof containing copper and/or silicon, and the protective film is aluminum oxide formed on the aluminum layer to protect it from corrosion by tetramethyl ammonium hydroxide (TMAH). The passivation layer is TiN, and the chemical reaction used is oxidation of the aluminum layer through defects in the overlying TiN layer by placing in an ozone asher.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.