Shielding strategy for mitigation of stray field for permanent magnet array
US11927549B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 2021 |
| Grant date | Mar 12, 2024 |
| Priority date | — |
| Expiry date | Sep 8, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present disclosure provides an inspection system and a method of stray field mitigation. The system includes an array of electron beam columns, a first permanent magnet array, and a plurality of shielding plates. The array of electron beam columns each includes an electron source configured to emit electrons toward a stage. The first permanent magnet array is configured to condense the electrons from each electron source into an array of electron beams. The first permanent magnet array is arranged at a first end of the array of electron beam columns. The plurality of shielding plates extend across the array electron beam columns downstream of the first permanent magnet array in a direction of electron emission. The array of electron beams pass through a plurality of apertures in each of the plurality of shielding plates, which reduces stray magnetic field in a radial direction of the array of electron beams.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.