Low open area and coupon endpoint detection
US12080574B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 17, 2020 |
| Grant date | Sep 3, 2024 |
| Priority date | — |
| Expiry date | Sep 29, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/2445
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The disclosure describes apparatus and method for detecting an endpoint in plasma-assisted wafer processing in a chamber. A fiber array comprising a plurality of fibers collects optical emission light from the chamber during the plasma-assisted wafer processing. The fiber array is split into two or more groups of fibers, each group carrying a portion of the light to a segment of a photodetector. Each segment of photodetector has a corresponding narrowband optical filter designed for a specific range of wavelengths. A computer processor analyzes detected signals from the plurality of segments of the photodetector, and determines, based on the analysis of the detected signals, an endpoint of the plasma-assisted wafer processing as indicated by the presence or the absence of the one or more chemical species in the chamber. The photodetector can be based on photomultiplier tube (PMT) array or based on photodiodes (e.g., avalanche photodiodes (APDs)).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.