Plasma etching apparatus
US5320704A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 27, 1991 |
| Grant date | Jun 14, 1994 |
| Priority date | — |
| Expiry date | Nov 27, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/3455
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A magnetron plasma etching apparatus comprises a chamber and a mount for supporting a substrate. A high-potential electrode connected to an RF power source is connected to the mount, and a low-potential electrode which is grounded is connected to the chamber. A rotary magnet is provided above the chamber, thereby generating a rotary magnetic field intersecting at right angles an electric field generated by both electrodes. An end-point detecting member for detecting an end-point of etching of the substrate is provided at the side of the chamber. The end-point detecting member collects mainly the light at a region near the rotation center of the magnetic field. That light component of a spectrum, which varies greatly with the progress of the etching, is extracted from the collected light, and the intensity of the light of this spectrum is converted to a first electric signal. The intensity of the collected light is converted to a second electric signal. The end-point detecting means calculates a ratio of the first and second electric signals, and the end-point of the etching is detected on the basis of the ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.