Apparatus and method for forming features on a substrate
US6461774B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 27, 1998 |
| Grant date | Oct 8, 2002 |
| Priority date | — |
| Expiry date | Aug 27, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/34
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A phase-shifting lithographic mask, a method for its fabrication, and a method for its use in forming field-emission display emitters is described. The mask is made from a plate and has field and pattern regions that both transmit light of a given wavelength. The pattern region is a plurality of regularly spaced etched regions of the plate, with the optical path length of the pattern region differing from the optical path length of the field region by an odd integer multiple of one-half the light wavelength. Use of phase-shifting lithography improves depth-of-focus, and correspondingly relaxes planarity requirements. The pattern region of the mask is sized to expose a photoresist layer used in fabricating field-emission display emitters in just a single light exposure, thereby avoiding the disadvantages associated with conventional dual pass phase-shifting lithography.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.