Multi-beam multi-column electron beam inspection system
US6844550B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 2003 |
| Grant date | Jan 18, 2005 |
| Priority date | — |
| Expiry date | Jul 29, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/2817
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A multi-column electron beam inspection system is disclosed herein. The system is designed for electron beam inspection of semiconductor wafers with throughput high enough for in-line use. The system includes field emission electron sources, electrostatic electron optical columns, a wafer stage with six degrees of freedom of movement, and image storage and processing systems capable of handling multiple simultaneous image data streams. Each electron optical column is enhanced with an electron gun with redundant field emission sources, a voltage contrast plate to allow voltage contrast imaging of wafers, and an electron optical design for high efficiency secondary electron collection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.