Overlay measuring method and overlay measuring apparatus using the same
US7894062B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 2007 |
| Grant date | Feb 22, 2011 |
| Priority date | — |
| Expiry date | Dec 22, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70633
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An overlay measuring apparatus includes a light source which generates visible light with a plurality of wavelengths, an optical module which selects visible light with a single wavelength from the visible light generated by the light source, makes the visible light with a single wavelength incident on a plurality of overlay patterns, and uses visible light reflected from the plurality of overlay patterns to project the overlay patterns with a predetermined color, an imaging unit which acquires images of the plurality of overlay patterns according to individual wavelengths of the visible light and acquires corresponding image signals, and a control unit which outputs a control signal to the optical module so that the optical module can project the overlay pattern with a specific color using information associated with the individual wavelengths of the visible light that is used to project the overlay pattern image selected by a selection unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.