Envelope follower end point detection in time division multiplexed processes
US7101805B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 2004 |
| Grant date | Sep 5, 2006 |
| Priority date | — |
| Expiry date | Nov 1, 2024 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB81C2201/0132
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention provides a method and an apparatus for establishing endpoint during an alternating cyclical etch process or time division multiplexed process. A substrate is placed within a plasma chamber and subjected to an alternating cyclical process having an etching step and a deposition step. A variation in plasma emission intensity is monitored using known optical emission spectrometry techniques. An amplitude information is extracted from a complex waveform of the plasma emission intensity using an envelope follower algorithm. The alternating cyclical process is discontinued when endpoint is reached at a time that is based on the monitoring step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.