Pneumatic polishing head for CMP apparatus
US5643061A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1995 |
| Grant date | Jul 1, 1997 |
| Priority date | — |
| Expiry date | Jul 20, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B37/32
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A polishing head for chemical-mechanical polishing apparatus includes a carrier plate having concentric, integral, cylindrical walls, an annular piston fitting within the outer of the cylindrical walls and a second piston fitting within the inner cylindrical wall and engaging the annular piston. Each piston defines a chamber with the carrier plate and the chambers are isolated from each other by a seal. Pneumatic fittings supply air or vacuum to each chamber. The second piston includes a cylindrical side wall and an integral bottom plate. The bottom plate is thicker in the center than at the side wall and the underside of the plate is covered with a wafer adhering layer. A retaining ring is attached to the lower edge of the annular piston. The retaining ring includes a peripheral groove for separating an outwardly extending flange from the main body of the ring. The underside of the ring includes one or more spiral grooves for circulating slurry about a wafer during polishing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.