Method and device for aligning a charged particle beam column
US7271396B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 4, 2002 |
| Grant date | Sep 18, 2007 |
| Priority date | — |
| Expiry date | Nov 4, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/221
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention provides a method for automatically aligning a beam of charged particles with an aperture. Thereby, the beam is defelcted to two edges of the aperture. From the signals required to obtain an extinction, a correction deflection field is calculated. Furter, a method for automatically aligning a beam of charged particles with an optical axis is provided. Thereby a defocusing is introduced and a signal calculated based on an introduced image shift is applied to a deflection unit. Further, a method for correction of the astigmatism is provided. Thereby the sharpness is evaluated for a sequence of frames measured whilst varying the signals to a stigmator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.