Plasma processing apparatus
US5779803A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Aug 13, 1996 |
| Grant date | Jul 14, 1998 |
| Priority date | — |
| Expiry date | Aug 13, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/32633
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus for subjecting a semiconductor wafer having an uncovered marginal portion, from which a photoresist film is removed, to an anisotropic etching. The apparatus comprises a process chamber which can be set to a vacuum. Upper and lower electrodes opposite to each other are provided in the process chamber. An etching gas is made into plasma between these electrodes. An electrostatic chuck is arranged on the lower electrode. A wafer is mounted on the electrostatic chuck. A ring made of dielectric material, movable upward and downward, is arranged between the electrodes. A central portion of the ring is formed as a hood having a recessed shape corresponding to the marginal portion of the wafer. During the etching, the hood covers the marginal portion of the wafer under a plasma sheath, so as to be out of contact with the wafer, thereby preventing the marginal portion of the wafer from being etched.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.