Method and apparatus for measurement and control of photomask to substrate alignment
US7875987B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 2007 |
| Grant date | Jan 25, 2011 |
| Priority date | — |
| Expiry date | Aug 20, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/975
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method, structure, system of aligning a substrate to a photomask. The method comprising: directing light through a clear region of the photomask in a photolithography tool, through a lens of the tool and onto a set of at least three diffraction mirror arrays on the substrate, each diffraction mirror array of the set of at least three diffraction mirror arrays comprising a single row of mirrors, all mirrors in any particular diffraction mirror array spaced apart a same distance, mirrors in different diffraction mirror arrays spaced apart different distances; measuring an intensity of light diffracted from the set of at least three diffraction mirror arrays onto an array of photo detectors; and adjusting a temperature of the photomask or photomask and lens based on the measured intensity of light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.