Surface treatment for micromachining
US6027571A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 1998 |
| Grant date | Feb 22, 2000 |
| Priority date | — |
| Expiry date | Jun 29, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32134
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A fine surface treatment for micromachining having an etching speed whose difference is smaller to oxide films each obtained by a different method as well as conditions of forming film or having different concentration of various impurities such as P, B and As in the film, and also having a practical etching speed to each of the films. The surface treatment for micromachining contains 0.1 to 8 weight percent of hydrogen fluoride and not less than 40 weight percent to not more than 47 weight percent of ammonium fluoride. It should be noted that it is preferable the surface treatment agent contains 0.001 to 1 weight percent of surfactant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.