Polishing apparatus including thickness or flatness detector
US5838447A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 1996 |
| Grant date | Nov 17, 1998 |
| Priority date | — |
| Expiry date | Jul 19, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/306
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A polishing apparatus polishes a workpiece such as a semiconductor wafer while detecting a thickness or a flatness of a surface layer of the workpiece on a real-time basis. The polishing apparatus includes a turntable with a polishing cloth mounted on an upper surface thereof, and a top ring disposed above the turntable for supporting a workpiece to be polished and such workpiece against the polishing cloth. The polishing apparatus also has a thickness detector for detecting the thickness of a surface layer of the workpiece supported by the top ring while the workpiece is being polished without exposing the workpiece. The thickness detector includes a sensor mounted in the turntable and including at least one light-emitting element for emitting light toward the surface layer of the workpiece and at least one light-detecting element for detecting light reflected from the surface layer of the workpiece.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.