Low-blur electrostatic transfer lens for multi-beam electron gun
US11562879B2 · kind B2 · utility
Assignees
Inventor
Key dates
| Filing date | Sep 15, 2020 |
| Grant date | Jan 24, 2023 |
| Priority date | — |
| Expiry date | Jun 8, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/31774
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electrostatic beam transfer lens for a multi-beam apparatus that includes a series of multiple, successive electrodes, such that an aperture bore of each electrode is aligned along an electron gun axis and is configured to allow multiple beams to pass therethrough. The first electrode in the series is a cylindrical electrode configured to receive the multiple beams at an entrance plane. The first electrode has a bore length and a bore diameter such that a ratio of bore diameter/bore length<0.3. The shape of the first electrode defines the electrostatic field penetration to the entrance plane of the first electrode to prevent lens focusing fields of the electrostatic beam transfer lens from extending through the first electrode and beyond the entrance plane, thus providing a uniform, flat electric field at the entrance area of the electrostatic transfer lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.