Method for determining lens errors in a particle-optical device
US7518121B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 2006 |
| Grant date | Apr 14, 2009 |
| Priority date | — |
| Expiry date | Oct 2, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/282
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to a method for determining lens errors in a Scanning Electron Microscope, more specifically to a sample that enables such lens errors to be determined. The invention describes, for example, the use of cubic MgO crystals which are relatively easy to produce as so-called ‘self-assembling’ crystals on a silicon wafer. Such crystals have almost ideal angles and edges. Even in the presence of lens errors this may give a clear impression of the situation if no lens errors are present. This enables a good reconstruction to be made of the cross-section of the beam in different under- and over-focus planes. The lens errors can then be determined on the basis of this reconstruction, whereupon they can be corrected by means of a corrector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.