Spectra based endpointing for chemical mechanical polishing
US7406394B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 2005 |
| Grant date | Jul 29, 2008 |
| Priority date | — |
| Expiry date | Dec 18, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3212
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Methods and apparatus for spectrum-based endpointing. An endpointing method includes selecting two or more reference spectra. Each 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 spectra is selected for particular spectra-based endpoint determination logic so that the target thickness is achieved when endpoint is called by applying the particular spectra-based endpoint logic. The method includes obtaining two or more current spectra. Each 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.