Method of making a twin alternating phase shift mask
US6277527A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1999 |
| Grant date | Aug 21, 2001 |
| Priority date | — |
| Expiry date | Apr 29, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/34
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A photolithographic mask comprises a first plurality of image segments etched into a mask substrate to a first level imparting a predetermined phase shift with respect to electromagnetic radiation of a predetermined frequency, preferably a 90.degree. phase shift, and a second plurality of image segments etched into the mask substrate to a second level imparting a phase shift of 180.degree. more or less than the phase shift of the first plurality of image segments with respect to the predetermined electromagnetic radiation, preferably a 270.degree. phase shift. The first and second segments are disposed adjacent each other on a substrate and positioned such that an intersection of the predetermined electromagnetic radiation passing through the segments causes printable images to be created below the substrate when exposed to the predetermined electromagnetic radiation. The mask may further include a blocking material for the electromagnetic radiation, adjacent at least one of the first and second segments or regions, of a configuration adapted to cause a printable image to be created below the mask when exposed to the predetermined electromagnetic radiation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.