Position detecting method and apparatus
US5200800A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 1992 |
| Grant date | Apr 6, 1993 |
| Priority date | — |
| Expiry date | May 29, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7076
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of detecting a position of a substrate having an alignment mark includes the steps of projecting a radiation beam from an optical head to the alignment mark such that the alignment mark produces a signal beam on the basis of which the position of the substrate is detected, forming a reference mark on the substrate at a position different from that of the alignment mark, projecting a radiation beam from the optical head to the reference mark, such that the reference mark produces a reference beam, detecting the relative positional deviation of the optical head relative to the reference mark on the basis of the produced reference beam, and adjusting the relative position of the optical head and the alignment mark on the basis of the detected relative positional deviation and, after the adjustment, detecting the position of the substrate on the basis of the produced signal beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.