Optical method and apparatus for inspecting large area planar objects
US6809809B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 4, 2003 |
| Grant date | Oct 26, 2004 |
| Priority date | — |
| Expiry date | Mar 4, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9501
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical inspection module is provided for detecting defects on a substrate having first and second opposite planar surfaces. The module includes a substrate holding position and first and second measurement instruments. The first instrument includes a first illumination path extending to the substrate holding position and having a grazing angle of incidence with the first surface, which illuminates substantially the entire first surface. A first optical element is oriented to collect non-specularly reflected light scattered by the first surface. A first photodetector has a plurality of pixels positioned within a focal plane of the first lens, which together form a field of view that covers substantially the entire first surface. The second instrument includes a sensor oriented for sensing a physical characteristic of the second surface when the substrate is held in the substrate holding position and the first surface is being illuminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.