Method and apparatus for optical emission end point detection in plasma etching processes
US5308414A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1992 |
| Grant date | May 3, 1994 |
| Priority date | — |
| Expiry date | Dec 23, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/32935
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for determining the time at which a plasma etching process should be terminated. The process generates at least one etch product species and a continuum plasma emission. The apparatus monitors the optical emission intensity of the plasma in a narrow band centered about a predetermined spectral line and generates a first signal indicative of the spectral intensity of the etch product species. The apparatus further monitors the optical emission intensity of the plasma in a wide band and generates a second signal indicative of the spectral intensity of the continuum plasma emission. The apparatus further monitors the magnitudes of the first and second signals and generates a termination signal when the magnitudes diverge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.