Wafer aligner system
US6275742A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1999 |
| Grant date | Aug 14, 2001 |
| Priority date | — |
| Expiry date | Apr 16, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S414/136
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An alignment device for use with a robot for manipulating and aligning a series of semiconductor wafers with respect to an edge fiducial and the center of each wafer is disclosed. The device includes a rotary vacuum chuck for holding a wafer, and an edge detector comprising a light source that extends across the wafer edge as it moves and creates a shadow that falls on a charge coupled device (CCD) below. Output data from the CCD relative to the wafer edge position is processed by a programmable logic circuit and converted to quadrature data which is fed to the logic section of a controller. The controller is programmed to calculate the location of the wafer fiducial relative to the chuck axis and further to calculate the angular and distance offset of the wafer center from the longitudinal axis of the robot arm so that the robot arm can be moved to center the wafer with its fiducial at a preselected location before the wafer is removed from the rotary chuck.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.