Wafer transfer system
US4836733A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1987 |
| Grant date | Jun 6, 1989 |
| Priority date | — |
| Expiry date | Dec 21, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/53087
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Wafer transfer apparatus for horizontal transfer of a wafer between a cassette and an input station of a vacuum processing system includes a wafer transfer arm with a primary section linked to a secondary section so as to move a wafer in a straight line to a location and orientation station and then to the input station. The actual location of the wafer center and the angular orientation of the wafer flat are determined, and the wafer is rotated to a desired angular orientation at the location and orientation station. A solar cell is used to sense actual wafer position by sensing the wafer edge as it is rotated. The required correction and rotation are calculated from the solar cell output. As the wafer is transferred to the input station, correcting displacements are added to the movement so that the wafer is accurately positioned at the input station. A strain gauge is used to reliably sense wafer presence or absence on the transfer arm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.