Photomask and methods for manufacturing and correcting photomask
US9519211B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 2015 |
| Grant date | Dec 13, 2016 |
| Priority date | — |
| Expiry date | Mar 27, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/80
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention provides a halftone mask comprising an assist pattern and a manufacturing method of the halftone mask, which uses an ArF excimer laser as an exposing source, is used for a projection exposure by an off axis illumination, does not resolve the assist pattern while keeping the focal depth magnification effect as the assist pattern, and may form a transferred image having high contrast of a main pattern. A photomask is a photomask comprising the main pattern which is transferred to a transfer-target surface by the projection exposure and the assist pattern which is formed nearby the main pattern and not transferred, characterized in that the main pattern and the assist pattern are each constituted from a semi-transparent film made of the same material, a retardation of 180° is generated between the light transmitting through the main pattern and the light transmitting through a transparent region of a transparent substrate, and a predetermined retardation within the scope of 70° to 115° is generated between the light transmitting through the assist pattern and the light transmitting through the transparent region of the transparent substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.