Chromeless phase shift lithography (CPL) masks having features to pattern large area line/space geometries
US7179570B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 2005 |
| Grant date | Feb 20, 2007 |
| Priority date | — |
| Expiry date | Dec 2, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/34
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A chromeless phase shift lithography (CPL) mask is described herein. The CPL mask includes a reticle having a phase-shifting feature pattern to produce a projected aerial image for patterning one or more large resist areas on a semiconductor substrate. The phase-shifting feature pattern includes an inner pattern comprising a plurality of phase-shifting features interspersed with non-phase-shifting areas. The phase-shifting features and the non-phase-shifting areas are arranged in a substantially alternating two-dimensional pattern surrounded by a substantially-filled phase-shifting peripheral area having a perimeter forming a pattern outline that is similar to an outline of the one or more large resist areas. Light that passes through the phase-shifting features and the phase-shifting peripheral area is phase-shifted by approximately 180 degrees from light passing through the non-phase-shifting areas of the CPL mask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.