Method for measuring wafer thickness
US6473987B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1999 |
| Grant date | Nov 5, 2002 |
| Priority date | — |
| Expiry date | Dec 28, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B5/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A wafer edge grinding or polishing machine is provided with a pair of chucks for engaging a wafer therebetween, a fixed reference surface and a sensor which is movable with a movable chuck. Measurements are made by the sensor relative to the fixed reference plane when the movable chuck is in engagement with the opposite chuck without a wafer therebetween in order to obtain a standard measurement value. With a wafer between the chucks, the sensor obtains an actual measurement value relative to the fixed reference surface. A calculator determines the difference between the standard and actual measurements values and displays the difference as the thickness of the wafer. Multiple sensors may be used to obtain multiples readings which are averaged by the calculator to obtain a thickness measurement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.