Method of measuring pore depth on the surface of a polishing pad
US6745631B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 9, 2003 |
| Grant date | Jun 8, 2004 |
| Priority date | — |
| Expiry date | May 9, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/2638
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of measuring pore depth on the surface of a polishing pad during processing. In the present invention, a planar ultrasound sensing device is disposed a predetermined distance above the surface of a polishing pad. The planar ultrasound sensing device sends out a plurality of ultrasound signals to the surface and the pores therein, and receives a plurality of reflected signals from the pad surface and constituent pores. The difference between pore depth and the surface is determined to establish first depth difference data according to the time delay in the reflected signals. The polishing pad is rotated to obtain second to Nth depth difference data. A relational image relative to the surface and the pores of the polishing pad is obtained according to the first to Nth depth difference data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.