Negative ion extractor for a plasma etching apparatus
US4158589A · kind A · utility
48Cited by
12References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1977 |
| Grant date | Jun 19, 1979 |
| Priority date | — |
| Expiry date | Dec 30, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/08
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Process and apparatus for use in extracting negative ions from a plasma which is particularly useful in reactive ion etching of metals, silicon and oxides and nitrides of silicon in the manufacture of semiconductor devices. A magnetic field is employed in the apparatus and, herein, is created by a novel grid, through which negative ions pass to a surface, such as one to be etched, while free electrons are prevented from passing through the grid and out of the plasma. The novel process utilizes negative ions which have a large fraction in the atomic state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.