Multi-beam hybrid solenoid lens electron beam system
US6710361B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 2002 |
| Grant date | Mar 23, 2004 |
| Priority date | — |
| Expiry date | Apr 30, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/147
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A multi-beam e-beam system employs a set of independently controllable (for blanking and deflection) subsystems placed in a solenoid field, each system having a demagnifying lens comprising at least one passive pole piece, so that the final image demagnifies imperfections in the upstream electron beam. Upper and lower sections of the system employ the focusing effect of the solenoid field to form an image at a shaping aperture and a demagnified image of the beam at the shaping aperture on the workpiece. Small focus corrections due to magnetic lens field non-uniformity and/or target height variations, are accomplished with an electrostatic unipotental lens built into the pole pieces and target voltage variations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.