Particle-beam column corrected for both chromatic and spherical aberration
US9275817B2 · kind B2 · utility
Inventor
Key dates
| Filing date | Mar 23, 2013 |
| Grant date | Mar 1, 2016 |
| Priority date | — |
| Expiry date | Mar 23, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/31749
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An objective lens for use in probe-forming particle-optical columns such as focused ion beam equipment, scanning electron microscopes, and helium microscopes is described. It comprises two interleaved (quadrupole/octopole) lenses and two or three ancillary octopole lenses, and is capable of simultaneous compensation of spherical (Cs) and chromatic (Cc) aberrations of the objective lens alone or of the complete particle-optical column. Additional apparatus comprising a gridded aperture and position-sensitive detector is specified, together with a method to measure and minimize all of the five independent third-order aberration coefficients of the objective lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.