Method and apparatus for controlling a calibration cycle or a metrology tool
US7262865B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 2004 |
| Grant date | Aug 28, 2007 |
| Priority date | — |
| Expiry date | Apr 2, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/20
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for controlling when a calibration cycle is started for a metrology tool. The method and apparatus exploits a correlation between a drift of a first parameter (e.g., film thickness measurement drift) and a drift of a second parameter (e.g., CD measurement drift). One embodiment of the method comprises measuring a film thickness on one or more reference substrates to determine when a drift component of these measurements exceeds a pre-determined range and thereafter calibrating the metrology tool when the drift component of the film thickness measurements exceeds the pre-determined range. Generally, the drift of the film thickness measurement will occur prior to substantial drift of the CD measurement occurring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.