Method for chemical mechanical polishing using synergistic geometric patterns
US6290578A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 1999 |
| Grant date | Sep 18, 2001 |
| Priority date | — |
| Expiry date | Oct 13, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B49/00
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method for planarizing the surface of a wafer against a polishing pad includes the steps of securing the wafer in a carrier, pressing the wafer against the polishing pad, rotating both the wafer and pad, and moving the wafer across the polishing pad to create one or more geometric patterns relative to the pad. Geometric patterns employed by the present method include a `figure eight`, an elliptical pattern, and a peanut-shaped pattern. In one embodiment of the invention, both a `figure eight` pattern and an elliptical pattern are used during a single planarizing operation. Bezier splines (curves) are used to create geometric patterns employed by the planarizing process. The use of Bezier splines requires that only two endpoints and two control points be stored in a memory device to represent the entire curve between the two endpoints, thus reducing the amount of data that has to be stored and transferred in order to operate a programmable wafer carrier in accordance with the present method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.