Sub-micron through-the-lens positioning utilizing out of phase segmented gratings
US5596413A · kind A · utility
84Cited by
2References
34Claims
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Key dates
| Filing date | Aug 17, 1995 |
| Grant date | Jan 21, 1997 |
| Priority date | — |
| Expiry date | Aug 17, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/70
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Through-the-lens alignment during deep UV lithographic processing in the manufacture of VLSI is accomplished without shifting the mask or wafer from the exposure position. Introduction and extraction of alignment light of actinic wavelength depends on beam routing due to diffraction from an interference grating. The path of alignment light is within the focusing system but does not impinge on the focused pattern.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.