Device for the detecting of charged secondary particles
US4983833A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 1989 |
| Grant date | Jan 8, 1991 |
| Priority date | — |
| Expiry date | Aug 14, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/24507
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A device for the detection of secondary electrons triggered at a large-area specimen is composed of a tube electrode arranged concentrically relative to the primary beam axis of an electron beam measuring device and an electrostatic or magnetic octupole for the deflection of the secondary electrons in the direction of a detector. An opposing electrical field is formed by two hemispherically shaped electrodes. The tube electrode which is arranged immediately above the specimen, and preferably has a circular cross-sectional area, whereby the tube diameter is selected larger than the diagonal of the specimen. An electrical extraction field that is rotationally symmetric with respect to the primary beam axis is generated inside the device. The secondary particles will be accelerated in the direction of the deflection unit. In the electrical extraction field, the particles are detected independently of the location of the respective measuring point inside the scanned field that is 20.times.20 cm.sup.2 in size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.