System and method for aerial image sensing
US6906305B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 2003 |
| Grant date | Jun 14, 2005 |
| Priority date | — |
| Expiry date | Nov 27, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7069
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A system to sense an aerial image produced by optical equipment used in, for example, semiconductor fabrication. In one embodiment, the system includes a photo-electron emission device which, in response to an aerial image projected thereon, emits electrons in a pattern corresponding to the light intensity distribution produced by the aerial image. Electron optics provides an enlarged pattern of the pattern in which the electrons are emitted. A sensing unit senses the enlarged pattern. In another embodiment, the system employs a photo-conducting layer to project the aerial image thereon. The photo-conducting layer, in response to the projection of the aerial image thereon, produces local charge depletion corresponding to the light intensity distribution. A steering device delivers electrons to the photo-conducting layer to produce local re-charging currents in proportion to the local charge depletion. A pattern corresponding to the aerial image may be obtained from the re-charging currents.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.