Method of feature exaction from time-series of spectra to control endpoint of process
US10262910B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 2016 |
| Grant date | Apr 16, 2019 |
| Priority date | — |
| Expiry date | Dec 23, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/24
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Methods and systems for using a time-series of spectra to identify endpoint of an etch process. One method includes accessing a virtual carpet that is formed from a time-series of spectra for the etch process collected during a training operation. And, running a fabrication etch process on a fabrication wafer, such that while the fabrication etch process is performed portions of a carpet defined from a time-series of spectral is generated for the fabrication etch process. Then, comparing the portions of the carpet of the fabrication etch process to the virtual carpet. End pointing is processed for the fabrication etch process when said comparing indicates that a desired metric has been reached for the fabrication wafer. In one example, said portions of the carpet include a current frame of captured spectra and at least one previous frame of captured spectra. The portions of the carpet of the fabrication etch process are fitted to the virtual carpet to identify a virtual frame number and associated floating parameters that are used in a correlation to predicted a value for the metric. Further, each of the carpets produced during the training operation and the virtual carpet are defi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.