Charged-particle-beam mapping projection-optical systems and methods for adjusting same
US6765217B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1999 |
| Grant date | Jul 20, 2004 |
| Priority date | — |
| Expiry date | Apr 28, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/30438
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Charged-particle-beam (CPB) mapping projection-optical systems and adjustment methods for such systems are disclosed that can be performed quickly and accurately. In a typical system, an irradiation beam is emitted from a source, passes through an irradiation optical system, and enters a Wien filter (“E×B”). Upon passing through the E×B, the irradiation beam passes through an objective optical system and is incident on an object surface. Such impingement generates an observation beam that returns through the objective optical system and the E×B in a different direction to a detector via an imaging optical system. An adjustment-beam source emits an adjustment beam used for adjusting and aligning the position of, e.g., the object surface and/or the Wien's condition of the E×B. The adjustment beam can be off-axis relative to the objective-optical system. For such adjusting and aligning, fiducial marks (situated, e.g., in the plane of the object surface) can be used that are optimized for the CPB optical system and the off-axis optical system. Desirably, the image formed on the detector when electrical voltage and current are not applied to the E&tim…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.