Polishing pad with radially extending tapered channels
US5645469A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 1996 |
| Grant date | Jul 8, 1997 |
| Priority date | — |
| Expiry date | Sep 6, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B37/26
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A polishing pad having a polishing surface with radially extending tapered channels is disclosed. The polishing surface includes an inner radius within an outer radius, and the channels extend from the inner radius to the outer radius. Preferably, the outer radius is spaced from an outer circumferential edge of the polishing surface, the inner radius is an inner circumferential edge of the polishing surface, and the channels taper laterally and vertically at the outer radius. The channels are dimensioned and configured to direct slurry from the inner radius to the outer radius. The channels can be shaped with opposing sidewalls that are parallel in a first portion and diagonally converge in a second portion to form a sunburst pattern, or alternatively, with opposing sidewalls that continuously curve in a first rotational direction to form a starfish pattern. A polishing method includes positioning a wafer over the outer radius while introducing a slurry to facilitate polishing the wafer, and positioning the wafer inside the outer radius while introducing a cleaning fluid to facilitate cleaning the wafer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.