Endpoint method using peak location of modified spectra
US8202738B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 2011 |
| Grant date | Jun 19, 2012 |
| Priority date | — |
| Expiry date | Apr 20, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of optically monitoring a substrate during polishing includes receiving an identification of a selected spectral feature and a characteristic of the selected spectral feature to monitor during polishing, measuring a first spectrum from the substrate during polishing, the first spectrum measured within an initial time following initiation of polishing, measuring a sequence of second spectra from the substrate during polishing, the sequence of second spectra measured after the initial time, for each second spectrum in the sequence of second spectra, removing the first spectrum from the second spectrum to generate a sequence of modified third spectra, determining a value of a characteristic of the selected spectral feature for each third spectrum in the sequence of third spectra to generate a sequence of values for the characteristic, and determining a polishing endpoint or an adjustment for a polishing rate based on the sequence of values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.