Sample inspection using interference and/or correlation of scattered superbroad radiation
US5905572A · kind A · utility
Inventor
Key dates
| Filing date | Aug 21, 1997 |
| Grant date | May 18, 1999 |
| Priority date | — |
| Expiry date | Aug 21, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B9/02091
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Embodiments of the present invention are inspection methods and inspection apparatus for use in inspecting a sample such a wafer, photomask, and the like used in the semiconductor industry to fabricate circuits, memory, and the like. An embodiment of the inventive inspection apparatus comprises: (a) a source of radiation which outputs superbroad inspection radiation and superbroad reference radiation; (b) a radiation applicator apparatus which applies the inspection radiation as input to a portion of the sample and which applies the reference radiation as input to a reference; and (c) a radiation collection apparatus which applies at least a portion of the inspection radiation scattered by the portion of the sample as input to a defect processor and which applies at least a portion of the reference radiation scattered by the reference as input to the defect processor; wherein the defect processor measures differences between the radiation scattered by the reference and the radiation scattered from the portion of the sample.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.