Automatic focusing system for scanning electron microscope equipped with laser defect detection function
US6621082B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 13, 2002 |
| Grant date | Sep 16, 2003 |
| Priority date | — |
| Expiry date | Jun 13, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/216
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A scanning electron microscope equipped with a laser defect detection function has an automatic focusing function that performs the steps of: obtaining a deviation (offset) amount between focal positions of an optical microscope and a scanning electron microscope; detecting a defect by a laser dark-field image of the optical microscope; analyzing the dark-field image to readjust a focus of the optical microscope to adjust a height of the optical microscope; and automatically adjusting a focus of the scanning electron microscope by adding a readjusted amount of the focus of the optical microscope to the offset amount before an observation is conducted by the scanning electron microscope.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.