Wafer inspecting apparatus
US6191849A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 24, 1998 |
| Grant date | Feb 20, 2001 |
| Priority date | — |
| Expiry date | Dec 24, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9505
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disclosed is a wafer inspecting apparatus suitable to determine whether a scattering substance is a surface foreign matter or an internal defect even if the particle size of the scattering substance is smaller than the wavelength of irradiation rays used for inspection. The wafer is obliquely irradiated with irradiation rays at the Brewster angle, and scattered rays which are scattered from a scattering substance on or in the wafer are detected at and angle 0.degree. and an angle of the Brewster angle or more by detectors. Then, it is determined whether the scattering substance is a surface foreign matter or an internal defect on the basis of a ratio between the intensities of the scattered rays detected by the detectors. The intensity of scattered rays which are scattered from a surface foreign matter and detected at an angle of the Brewster angle or more is larger than the intensity of scattered rays which are scattered from the foreign matter and detected at an angle 0.degree., and the intensity of scattered rays which are scattered from an internal defect and detected at an angle of the Brewster angle or more is smaller than the intensity of scattered rays which are scattered f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.