Spectrum based endpointing for chemical mechanical polishing
US7764377B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 2005 |
| Grant date | Jul 27, 2010 |
| Priority date | — |
| Expiry date | Nov 3, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67253
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for spectrum-based endpointing. An endpointing method includes selecting a reference spectrum. The reference spectrum is a spectrum of white light reflected from a film of interest on a first substrate and has a thickness greater than a target thickness. The reference spectrum is empirically selected for particular spectrum-based endpoint determination logic so that the target thickness is achieved when endpoint is called by applying the particular spectrum-based endpoint logic. The method includes obtaining a current spectrum. The current spectrum is a spectrum of white light reflected from a film of interest on a second substrate when the film of interest is being subjected to a polishing step and has a current thickness that is greater than the target thickness. The method includes determining, for the second substrate, when an endpoint of the polishing step has been achieved. The determining is based on the reference and current spectra.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.