Assembly for measuring a trench depth parameter of a workpiece
US5691540A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1996 |
| Grant date | Nov 25, 1997 |
| Priority date | — |
| Expiry date | Apr 30, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/22
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An assembly for measuring a trench depth parameter of a workpiece is disclosed. The assembly has an ultra-violet radiation source; a split fiber bundle having a first branch for propagating the ultra-violet radiation from the radiation source to a lens, and a second branch; a lens for focusing the UV radiation to the workpiece and refocusing an ultra-violet interference signal to the second branch; and a detector responsive to the ultra-violet interference signal received through the second branch. The detector transforms the ultra-violet interference signal to an electrical signal which is a measure of a trench depth of the workpiece. The ultra-violet interference signal is developed when ultra-violet radiation propagates through the workpiece and reflects from its base region to thereby interfere with ultra-violet radiation that is directly reflected by a workpiece surface which is different from the base region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.