TDI sensor in a darkfield system
US9891177B2 · kind B2 · utility
43Cited by
10References
41Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 3, 2014 |
| Grant date | Feb 13, 2018 |
| Priority date | — |
| Expiry date | Oct 13, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30148
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A wafer scanning system includes imaging collection optics to reduce the effective spot size. Smaller spot size decreases the number of photons scattered by the surface proportionally to the area of the spot. Air scatter is also reduced. TDI is used to produce a wafer image based on a plurality of image signals integrated over the direction of linear motion of the wafer. An illumination system floods the wafer with light, and the task of creating the spot is allocated to the imaging collection optics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.