Hydrostatic fluid bearing support with adjustable inlet heights
US6454641B1 · kind B1 · utility
Inventors
Key dates
| Filing date | Nov 7, 2000 |
| Grant date | Sep 24, 2002 |
| Priority date | — |
| Expiry date | Nov 7, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/302
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A polishing system such as a chemical mechanical belt polisher includes a hydrostatic fluid bearing that supports polishing pads and incorporates one or more of the following novel aspects. One aspect uses compliant surfaces surrounding fluid inlets in an array of inlets to extend areas of elevated support pressure around the inlets. Another aspect modulates or reverses fluid flow in the bearing to reduce deviations in the time averaged support pressure and to induce vibrations in the polishing pads to improve polishing performance. Another aspect provides a hydrostatic bearing with a cavity having a lateral extent greater than that of an object being polished. The depth and bottom contour of cavity can be adjusted to provide nearly uniform support pressure across an area that is surrounded by a retaining ring support. Changing fluid pressure to the retaining ring support adjusts the fluid film thickness of the bearing. Yet another aspect of the invention provides a hydrostatic bearing with spiral or partial cardiod drain grooves. This bearing has a non-uniform support pressure profile but provides a uniform average pressure to a wafer that is rotated relative to the center of the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.