Automatic alignment system
US4385839A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 31, 1980 |
| Grant date | May 31, 1983 |
| Priority date | — |
| Expiry date | Jul 31, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/70
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An electro-optical device for generating data signals representing relative displacement between a master reticle with an optical aperture pattern in an object plane and a workpiece with an image of the aperture pattern in an image plane comprises a reference detector for sensing reference radiation directed towards the aperture pattern and a convolution detector for sensing the reference radiation reflected by the image pattern. A processor compares the phase of a signal generated by the convolution detector to the phase of a signal generated by the reference detector and generates the data signals defining the relative displacement between the master and the workpiece.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.