Dynamically compensated objective lens-detection device and method
US6232601A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1999 |
| Grant date | May 15, 2001 |
| Priority date | — |
| Expiry date | Mar 23, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/28
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to a charged particle beam device and a method for inspecting a specimen, comprising a source for generating a charged particle beam, an objective lens with an optical axis for focussing said charged particle beam on a specimen, which consists of a magnetic lens and a superimposed electrostatic lens having at least two electrodes, deflection means for deflecting said charged particle beam on said specimen and detector means for detecting charged particles released at said specimen. The invention is further characterized by control means co-acting with said deflection means and one of the electrodes of the electrostatic lens for applying a dynamic voltage to said electrode, the amount of the voltage being dependent on the distance of said charged particle beam from said optical axis at the specimen, in order to increase the efficiency of detecting said charged particles released at image areas being located on the specimen with distance from the optical axis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.