Filters for cathodic arc plasmas
US6465780B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 2000 |
| Grant date | Oct 15, 2002 |
| Priority date | — |
| Expiry date | Mar 31, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/022
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Cathodic arc plasmas are contaminated with macroparticles. A variety of magnetic plasma filters has been used with various success in removing the macroparticles from the plasma. An open-architecture, bent solenoid filter, with additional field coils at the filter entrance and exit, improves macroparticle filtering. In particular, a double-bent filter that is twisted out of plane forms a very compact and efficient filter. The coil turns further have a flat cross-section to promote macroparticle reflection out of the filter volume. An output conditioning system formed of an expander coil, a straightener coil, and a homogenizer, may be used with the magnetic filter for expanding the filtered plasma beam to cover a larger area of the target. A cathodic arc plasma deposition system using this filter can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.