Weighted regression of thickness maps from spectral data
US8992286B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 2013 |
| Grant date | Mar 31, 2015 |
| Priority date | — |
| Expiry date | Aug 25, 2033 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B37/013
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of controlling a polishing operation includes measuring a plurality of spectra at a plurality of different positions on a substrate to provide a plurality of measured spectra. For each measured spectrum of the plurality of measured spectra, a characterizing value is generated based on the measured spectrum. For each characterizing value, a goodness of fit of the measured spectrum to another spectrum used in generating the characterizing value is determined. A wafer-level characterizing value map is generated by applying a regression to the plurality of characterizing values with the plurality of goodnesses of fit used as weighting factors in the regression. A polishing endpoint or a polishing parameter of the polishing apparatus is adjusted based on the wafer-level characterizing map, and the substrate or a subsequent substrate is polished in the polishing apparatus with the adjusted polishing endpoint or polishing parameter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.