Wafer carrier rotating head assembly for chemical-mechanical polishing apparatus
US5868609A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 1997 |
| Grant date | Feb 9, 1999 |
| Priority date | — |
| Expiry date | Apr 14, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B37/30
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A chemical-mechanical polishing apparatus includes a wafer carrier with a very low center of gravity which allows pressure to be applied evenly on a wafer being polished. The wafer carrier includes top, center, and bottom mating subassemblies with only the center and bottom subassembly or wafer holder actually rotating. The bottom of the central subassembly and the top of the bottom subassemblies are shaped as negative and positive, mating truncated pyramids with a downward extension at the center axis of the central subassembly which terminates in a ball in a recess in the top of the lower subassembly. The ball is positioned as low as possible to provide a very low center of gravity to ensure even pressure distribution over a wafer being polished. The truncated pyramidal shapes are to provide a geometry which exhibits a rigid structure with incrementally decreasing mass with distance from the central axis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.