Method of wet etching aluminum oxide to minimize undercutting
US5876614A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1997 |
| Grant date | Mar 2, 1999 |
| Priority date | — |
| Expiry date | Apr 18, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/0276
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The method of wet etching an aluminum oxide substrate deposits a thin layer of titanium film or chromium film on the aluminum oxide surface prior to the application of the photo-resist coating to form a barrier between the aluminum oxide and the photo-resist. This barrier layer inhibits the reaction between the aluminum oxide and the photo-resist during the photolithographic process. The undercutting of the aluminum oxide in the wet etching process is therefore controlled by the deposition of the barrier layer comprising the thin layer of titanium film or chromium film. The titanium film used is nominally 30 .ANG. thick to obtain the beneficial effects noted above while the chromium film would be approximately 1000 .ANG. thick.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.