Electrostatic deflection system with low aberrations and vertical beam incidence
US7315029B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 2005 |
| Grant date | Jan 1, 2008 |
| Priority date | — |
| Expiry date | Jan 7, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/3175
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Embodiments of the present invention may be utilized to improve electron beam deflection. One embodiment provides an electrostatic deflection system with electrodes that minimize aberrations and to achieve vertical incidence simultaneously. By using at least two stages of deflection for a deflection direction, the present invention allows the deflected electron beam to pass a back focal plane of an objective lens while deflection capacitors are not disposed across the back focal plane. As a result, deflection electrodes can have an angle of 120° to minimize aberrations and simultaneously achieve vertical incidence of the electron beam on a target to avoid distortions or changes in magnification with height variations of the target or focus variations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.