Method and apparatus of monitoring polishing pad wear during processing
US6045434A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 1997 |
| Grant date | Apr 4, 2000 |
| Priority date | — |
| Expiry date | Nov 10, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B37/005
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for monitoring polishing pad wear during processing is developed to extend the pad's useful life, and maintain pad uniformity. This is accomplished in the present invention by measuring and monitoring the diminished pad thickness using a non-intrusive measurement system, and creating a closed-loop system for adjusting the chemical-mechanical polishing tool process parameters. The non-intrusive measurement system consists of an interferometer measurement technique utilizing ultrasound or electromagnetic radiation transmitters and receivers aligned to cover any portion of the radial length of a polishing pad surface. The measurement system is sensitive to relative changes in pad thickness for uniformity, and to abrupt changes such as detecting wafer detachment from the CMP wafer carrier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.