Apparatus and method for reducing space charge of ion beams and wafer charging
US6313428A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1999 |
| Grant date | Nov 6, 2001 |
| Priority date | — |
| Expiry date | Oct 12, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/31701
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus for ion beam neutralization is disclosed in this invention. The apparatus is a plasma flood source with an arc discharge chamber enclosed in a source housing with sufficient cooling so that the housing temperature is near room temperature. Arc discharge between a filament and the arc chamber ionizes the bleeding gas atoms or molecules in the arc chamber and produces plasma. The low energy electrons together with ions in the plasma drift out of the arc chamber and neutralize the passing ion beam. The sufficiently cooled source housing prevents radiation to the processed wafers, reduces metal particle concentration in the plasma and therefore metal contamination on the wafers, and keeps beamline pressure low while more electrons are extracted from the flood source through the apertures with larger area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.