Method and apparatus for inspecting pattern defects
US7218389B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 2002 |
| Grant date | May 15, 2007 |
| Priority date | — |
| Expiry date | Aug 6, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/1045
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A pattern defect inspection apparatus is capable of detecting defects, without being affected by non-uniform thickness of a thin film formed on a sample, even when using monochromatic light, such as a laser. The apparatus comprises a laser to illuminate a sample, coherence suppression optics to reduce laser beam coherence, a condenser to condense the laser beam onto a pupil plane of an objective lens, and a detector to detect the light reflected from a circuit pattern formed on a sample. The condenser is designed so that the intensity of light illuminating the sample under test can be partially adjusted according to the type of laser beam illumination condensed on the pupil of the objective lens. Variations in reflected light intensity caused by non-uniform film thickness on the surface of the sample are therefore reduced, and shading is minimized in the detected image to allow detecting of fine defects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.