Photomask and methods for manufacturing and correcting photomask
First Claim
1. A correcting method of a photomask using an ArF excimer laser as an exposing source, being used for a projection exposure by an off axis illumination, and comprising on a principal plane of a transparent substrate a main pattern transferred to a transfer-target surface by the projection exposure and an assist pattern formed nearby the main pattern, in which a minimum pattern pitch of the main pattern on the transfer-target surface is 120 nm or less, in a case where the assist pattern is resolved on the transfer-target surface by the projection exposure;
- wherein a surface of the assist pattern to be resolved is-ground to make a film thickness of the assist pattern to be resolved thinner than a film thickness of the main pattern until the assist pattern is not resolved on the transfer-target surface.
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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.
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Citations
8 Claims
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1. A correcting method of a photomask using an ArF excimer laser as an exposing source, being used for a projection exposure by an off axis illumination, and comprising on a principal plane of a transparent substrate a main pattern transferred to a transfer-target surface by the projection exposure and an assist pattern formed nearby the main pattern, in which a minimum pattern pitch of the main pattern on the transfer-target surface is 120 nm or less, in a case where the assist pattern is resolved on the transfer-target surface by the projection exposure;
wherein a surface of the assist pattern to be resolved is-ground to make a film thickness of the assist pattern to be resolved thinner than a film thickness of the main pattern until the assist pattern is not resolved on the transfer-target surface. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
Specification