Multi-channel plasma discharge endpoint detection method
US5160402A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 24, 1990 |
| Grant date | Nov 3, 1992 |
| Priority date | — |
| Expiry date | May 24, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/32935
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A plasma discharge endpoint detection system and method characterized by a plurality of individual data channels which are combined to create a composite function representative of the conditions within a plasma etch chamber. Preferably, a number of the channels are representative of spectral components within the optical spectrum caused by the plasma discharge within the etch chamber. A multi-channel sensor assembly is provided for this purpose including a number of light-guides for guiding light from the plasma discharge to filters and photosensors associated with the multiple channels. Other channels can detect various conditions such as the D.C. bias on a cathode within the plasma etch chamber. The various channels are digitized, weighted and summed within a digital computer to create the composite function from which endpoint and other conditions within the chamber can be determined. The method is characterized by the weighting and summing of a plurality of data channels carrying information about the conditions within a plasma etch chamber to develop a composite function and then analyzing the composite function to determine endpoint and other conditions. The endpoint detecti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.