Etching of a phosphosilicate glass film selectively implanted with boron
US4634494A · kind A · utility
20Cited by
2References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1985 |
| Grant date | Jan 6, 1987 |
| Priority date | — |
| Expiry date | Jul 29, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/978
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The etch rate of phosphosilicate glass becomes lowered as boron ions are implanted therein. In accordance with the principle of the present invention, boron ions are implanted into a phosphosilicate glass film selectively in location or concentration and the thus boron-implanted phosphosilicate glass film is etched by an etchant, for example buffered hydrofluoric acid solution, to etch an intended portion of the phosphosilcate glass film preferentially thereby defining a hole, such as a contact hole, or substantially flat surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.