Photo mask and exposure method using same
AssigneeNikon Corporation
InventorsNaomasa Shiraishi, Nobutaka Magome, Shigeru Hirukawa
Life of this patent
Estimating the term…
Abstract
A photo mask for lithography process form a high contrast image. The photo mask includes a light transparent portion and a light shielding portion, at least a part of which has a multilayer construction, wherein an the edge portion of the shielding portion has a different light transmissivity than a central portion surrounded by the edge portion.
Claims12
A photo mask having a transparent portion, which transmits an exposure beam, a first pattern formed on said transparent portion, and a second pattern formed on said transparent portion, said mask comprising:
- said first pattern having an attenuation portion having a transmissivity of 1-15% to said exposure beam, and a phase conversion portion, which converts exposure beam phases;
- and
- said second pattern having an attenuation portion, which has a multi-layer structure having at least a first layer and a second layer, said first layer and said second layer reducing the exposure beam with said second layer superimposed on the first layer for forming an edge portion surrounding a center portion of said first layer;
- wherein said edge portion of said multi-layer structure has a different transmissivity than said transparent portion and the center portion surrounded by said edge portion.
A substrate having a pattern formed thereon by exposure to an exposure beam using a photo mask, said photo mask comprising:
- a transparent portion, which transmits said exposure beam substantially without attenuation;
- a first portion having an attenuation portion having a transmissivity of 1-15% to said exposure beam, and a phase conversion portion which converts exposure beam phases;
- and a second portion having an attenuation portion composed of a multi-layer structure comprising at least a first layer and a second layer in which each layer has a substantially different transmittance relative to each other and to said exposure beam, with said second layer superimposed on the first layer for forming an edge portion surrounding a center portion of said first layer.
Dependencies are inferred from the claim text.