Method and system for improving focus accuracy in a lithography system
US6859260B2 · kind B2 · utility
7Cited by
4References
51Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 25, 2001 |
| Grant date | Feb 22, 2005 |
| Priority date | — |
| Expiry date | Dec 30, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/41415
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A focus system that includes a calibration subsystem and a control subsystem. The control subsystem, which includes a control sensor, is in close proximity to the exposing of an image. The calibration subsystem, which includes a calibration sensor and a control sensor, is located remotely from, or off-axis with respect to, the exposing of an image. By separating calibration and control functions, the functional requirements can be separated into two (or more) types of sensors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.