Apparatus and method of producing a negative ion plasma
US6051151A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1997 |
| Grant date | Apr 18, 2000 |
| Priority date | — |
| Expiry date | Nov 12, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05H1/46
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus and method of producing a negative ion plasma for use in manufacturing of microelectronic devices, particularly etching of microelectronic patterns in semiconductor wafers. A negative ion plasma is produced from a hot electron plasma formed by a RF or UHF plasma source. The negative ion plasma includes positive ions, negative ions and relatively cold electrons, such electrons having an effective electron temperature or average energies less than that for maintaining the plasma. The fields producing the hot plasma are isolated from the negative ion plasma in a cold plasma region by a magnetic filter. The magnetic filter confines the plasmas to provide plasma uniformity at a work piece being etched by the negative ion plasma. The magnetic filter further prevents hot electrons originating in the hot electron plasma from diffusing into the negative ion plasma, while allowing positive ions and cold electrons to diffuse from the hot plasma to the negative ion plasma. An RF bias on the work piece accelerates the positive ions, electrons and/or negative ions to the work piece being etched.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.