Method and apparatus for inspecting defect
US9535013B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 2011 |
| Grant date | Jan 3, 2017 |
| Priority date | — |
| Expiry date | Jul 28, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/956
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In inspecting a substrate having a transparent oxide film or a metal film formed on a surface thereof by using a dark field type inspection apparatus installing a laser light source, an illuminating beam having a high coherence causes variations in reflection strength due to multiple interferences within the transparent oxide film or an interference of scattered beams due to the surface roughness of the metal film occurs and which leads to degradation in the sensitivity of defect detection. The present invention solves the problem by providing a low-coherence but high-brightness illumination using a highly directive broadband light source, and a system in which the conventional laser light source is simultaneously employed to selectively use the light sources, thereby enabling a highly sensitive inspection according to the condition of a wafer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.