In-situ defect monitor and control system for immersion medium in immersion lithography
US7224456B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 2004 |
| Grant date | May 29, 2007 |
| Priority date | — |
| Expiry date | Jul 8, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2015/0011
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method for detecting bubbles in a lithographic immersion medium and for controlling a lithographic process based at least in part on the detection of bubbles is provided. A bubble monitoring component emits an incident beam that passes through the immersion medium and is incident upon a substrate to produce a reflected and/or diffracted beam(s). The reflected and/or diffracted beam(s) is received by one or more optical detectors. The presence or absence of bubbles can be derived from information extracted by scatterometry from the reflected and/or diffracted beams. A process control component interacts with a positioning component and an optical exposure component to alter a lithographic process based at least in part on the results of the scatterometry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.