Electron beam apparatus
US6504164B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 2000 |
| Grant date | Jan 7, 2003 |
| Priority date | — |
| Expiry date | Dec 19, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/141
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention is to observe semiconductor wafers with higher resolution at a low acceleration voltage—in particular, achieving such high-resolution observability when a wafer is inclined or tilted at large angles. A composite lens is used which consists essentially of a single-pole or monopole magnetic field type lens and an electrostatic field invasive lens whereas an electrode of the electrostatic field invasive lens which opposes the wafer is made of a magnetic material while letting a high voltage of the negative polarity be applied to this electrode and the wafer. Even when the wafer is tilted, any astigmatism and axis failure will hardly occur.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.