Determination of film thickness during chemical mechanical polishing
US7751609B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 20, 2000 |
| Grant date | Jul 6, 2010 |
| Priority date | — |
| Expiry date | Feb 11, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/26
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method and apparatus is provided for determining thickness of films or layers during chemical-mechanical planarization/polishing (CMP) of a semiconductor substrate or wafer in situ. The method may be used to determine end-point during CMP especially of oxide films deposited on the substrate or wafer. In one embodiment, the method includes: a) capturing images of the surface of the substrate using high speed imaging; b) performing pattern recognition on the captured images; c) selecting one of the captured images based on the pattern recognition; and d) converting the selected image into a thickness measurement. In one form, the high speed imaging comprises a high speed camera, while in another form, the high speed imaging comprises a conventional camera and a laser pulse or flash tube. In yet another embodiment, reflective laser interference patterns of the substrate are captured and analyzed for interference pattern changes that can signal a practical end-point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.