Plasma ashing apparatus
US5228052A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 1991 |
| Grant date | Jul 13, 1993 |
| Priority date | — |
| Expiry date | Sep 11, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/334
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A plasma ashing apparatus has a vacuum treatment chamber for receiving therein a substrate coated with a resist film, a reactive gas introduction pipe equipped with a plasma applicator, a vacuum exhaust pipe, a heating means for heating the substrate, and two pieces of electrodes disposed in parallel to each other. One of the electrodes is a substrate electrode and the other thereof is a circular counter electrode. These two electrodes are commonly connected to an RF power source to thereby constitute a cathode electrode. Multiple concentric perforations are formed in the counter electrode except for a rib portion. A central perforation is formed in the center of the counter electrode. The concentric perforations are formed at every distance, from the center, equivalent to a diameter of the central perforation, while leaving circular electrode surfaces corresponding in width to a radius of of the perforation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.