Optical auto focusing system and method for electron beam inspection tool
US7767982B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 2007 |
| Grant date | Aug 3, 2010 |
| Priority date | — |
| Expiry date | Apr 24, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/2817
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and system for inspecting a semiconductor wafer. The method includes providing an illumination flux through a pattern plate and a lens to a surface of a specimen to project a pattern onto the surface of the specimen. The pattern is associated with the pattern plate. Additionally, the method includes detecting the illumination flux reflected from the surface of the specimen with a detector, processing information associated with the detected illumination flux, and generating a first image based on at least information associated with the detected illumination flux. The first image includes a first image part for the pattern and a second image part for the specimen. Moreover, the method includes adjusting the lens to a state in order to achieve a first predetermined quality for the first image part, and moving the specimen to a first position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.