Apparatus for optical inspection of wafers during polishing
US6368181B1 · kind B1 · utility
10Cited by
49References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 4, 2000 |
| Grant date | Apr 9, 2002 |
| Priority date | — |
| Expiry date | Feb 4, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An optical system is disclosed for the inspection of wafers during polishing which also includes a measurement system for measuring the thickness of the wafer's top layer. The optical system views the wafer through a window and includes a gripping system, which places the wafer in a predetermined viewing location while maintaining the patterned surface completely under water. The optical system also includes a pull-down unit for pulling the measurement system slightly below the horizontal prior to the measurement and returns the measuring system to the horizontal afterwards.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.