Method for inspecting defects and defect inspecting apparatus
US8599379B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 2009 |
| Grant date | Dec 3, 2013 |
| Priority date | — |
| Expiry date | Jun 9, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Light from a light source device (4) is polarized through a polarizer (5) and is caused to impinge obliquely on an object (W) to be inspected. The resulting scattered light (SB) is received by a CCD imaging device (7) having an element (9) for separating scattered light disposed in a dark field. Component light intensities are worked out for an obtained P-polarized component image and an obtained S-polarized component image and a polarization direction is determined as a ratio of them. The component light intensities and the polarization directions are determined from images obtained by imaging of the light scattering entities in a state where stress is applied to the object to be inspected and in a state where stress is not applied thereto. The component light intensities and the polarization directions are compared with predetermined threshold values. As a result, defects in the inspection object, such as internal deposits or cavity defects, foreign matter or scratches on the surface or cracks in the surface layer can be detected with high precision and the defects can be classified by identifying the type of the defect.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.