Real-time control of chemical-mechanical polishing processes using a shaft distortion measurement
US6213846A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 1999 |
| Grant date | Apr 10, 2001 |
| Priority date | — |
| Expiry date | Jul 12, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B49/16
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method is provided for detecting the endpoint of a film removal process such as chemical-mechanical polishing (CMP). The process uses a device having a shaft, and friction in the film removal causes torque on the shaft. Two axially displaced reflecting portions are provided on the shaft. Light reflected from these portions generates first and second reflected signals, respectively. A phase difference between the reflected signals is detected, and an output signal is generated in accordance therewith. A change in the output signal indicates a change in deformation of the shaft resulting from change in the torque, thereby indicating the endpoint of the film removal process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.