Phase-shifting transparent lithographic mask for writing contiguous structures from noncontiguous mask areas
US5362584A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 1993 |
| Grant date | Nov 8, 1994 |
| Priority date | — |
| Expiry date | Apr 2, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70283
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A plurality of noncontiguous polygonal regions of phase-shifting material have edges spaced apart less than the distance at which images of said edges would separate. The edges of the regions of phase-shifting material have differing arbitrarily selectable angular orientations (nonparallel as well as parallel) on a nonphase-shifting material. The noncontiguous phase-shifting regions may be arranged in a matrix of parallel columns and rows to facilitate fabrication and facilitate writing of the phase-shifting regions in any arbitrary pattern on an image plane. At least one of the phase-shifting regions constitutes a connective phase-shifting region with edges spaced from edges of adjacent ones of the phase-shifting regions to create a pattern with a continuous body of photoresist covering areas corresponding to the phase-shifting regions upon exposure of the mask. The phase-shifting regions may have different transmission coefficients to provide differing degrees of transparency or different degrees of phase shift to provide differing degrees of image intensity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.