Fiber optical sensor embedded into the polishing pad for in-situ, real-time, monitoring of thin films during the chemical mechanical planarization process
US6780085B2 · kind B2 · utility
Inventor
Key dates
| Filing date | Nov 23, 2001 |
| Grant date | Aug 24, 2004 |
| Priority date | — |
| Expiry date | Nov 28, 2021 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B49/12
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An apparatus is disclosed which improves the optical monitoring of semi-conductor wafers undergoing chemical mechanical planarization. The apparatus consists of two assemblies. Firstly, a fiber optical wave-guide assembly installed within the polishing pad during the pad's construction. This assembly forms an integrated optical waveguide originating from the center of rotation of the polishing pad and terminating at a location within the wafer track. Secondly, a vacuum hub, tube, and angular encoder assembly, which provides light coupling to the center of rotation of the polishing pad and also provides resolution of the angular position and speed of the polishing pad, polishing table, and optical waveguide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.