Method and apparatus for reducing etching erosion in a plasma containment tube
US5423942A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1994 |
| Grant date | Jun 13, 1995 |
| Priority date | — |
| Expiry date | Jun 20, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/935
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus is provided for reducing wall erosion in a plasma containment tube (20), such as, for example, a quartz plasma tube (20) used in a microwave-induced plasma reaction process for etching semiconductor wafers. A pure benign or non-corrosive gas (Ar) is introduced into the "upstream" section (22a) of the tube (22), where the microwave energy is imparted to create a plasma. The activated benign gas flows "downstream" through a flange (28), preferably made of quartz, which is seated on o-rings (50) inside a water-cooled metal flange (48). These sealing o-rings (50) are thus cooled and removed from the ultraviolet light created by the plasma. The corrosive etchant gas (SF.sub.6) is introduced into the "downstream" section (22b) of the tube (22) beyond the flange (28), where it is activated by the benign gas (Ar). The benign gas (Ar) flows principally along the inner sidewalls of the tube (22), and the etchant gas (SF.sub.6) is thus principally contained by the benign gas (Ar) in the center of this section (22b) of the tube. This "downstream" section (22b) of the tube (22) is surrounded by a water jacket (24), which channels coolant around the outer surface of the tu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.