Surface defect test method and surface defect tester
US5898491A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1998 |
| Grant date | Apr 27, 1999 |
| Priority date | — |
| Expiry date | Mar 27, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The surface defect test method and tester according to the invention comprises a sensitivity calibration disk formed with n (n is an integer equal to or larger than 2) false defect rows each including 3 or more false defects each formed in a radial or peripheral direction provided in the peripheral direction of the calibration disk at a predetermined angle pitch. The false defects of each false defect row take in the form of protrusions or recesses having substantially the same size, adjacent ones of the false defects are physically separated by a predetermined distance larger than a width of a laser spot and the false defects of a certain one of the false defect rows are different in size from the false defects of other false defect rows, regulating the detection sensitivity according to a result of the test, producing, from a result of a test of the calibration disk with the regulated detection sensitivity, data relating a level of a detection signal to a size of the false defect as a reference data for determination of the size and obtaining the size of the defect from the level of the detection signal when the disk to be tested on defect on the basis of the reference data for d…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.