Environmental scanning electron microscope
US5362964A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 1993 |
| Grant date | Nov 8, 1994 |
| Priority date | — |
| Expiry date | Jul 30, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/2605
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An environmental scanning electron microscope which achieves image resolution comparable to that of a conventional SEM. A biased ring electrode which detects secondary electron signals emanating from the surface of the specimen is provided in the specimen chamber. A biased pressure limiting aperture electron detector is also provided to reduce signals emanating from backscattered electrons and to reduce signal noise generated by the electron beam. This environmental SEM also optimizes the signal amplification of the secondary electrons following detection thereof, such that the detector noise is reduced below the noise in the signal itself, while still maintaining an overall bandwidth that is suitable for setting up the image. An optical window system is also provided in this environmental SEM which allows the user to easily switch between the normal environmental SEM electron image (limited to 0.5 mm in diameter) to an optical light view of the sample that covers a field-of-view of up to about 7 to 10 mm. Moreover, the construction of this environmental SEM provides for a take-off angle for the X-ray detectors (EDX detectors) which is comparable to the take-off angle in for an EDX…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.