Automated focusing of electron image
US7041976B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 2003 |
| Grant date | May 9, 2006 |
| Priority date | — |
| Expiry date | Nov 3, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/2817
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
One embodiment disclosed relates to a method for automated focusing of an electron image. An EF cut-off voltage is determined. In compensation for a change in the EF cut-off voltage, a focusing condition is adjusted. Adjusting the focusing condition may comprise, for example, adjusting a wafer bias voltage in correspondence to the change in cut-off voltage. Another embodiment disclosed relates to a method for automated focusing of an electron image in a scanning electron imaging apparatus. A focusing condition of a primary electron beam in a first image plane is varied so as to maximize an intensity of a secondary electron beam through an aperture in a second image plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.