Microlithographic device, microlithographic assist features, system for forming contacts and other structures, and method of determining mask patterns
First Claim
1. A microlithographic mask for forming a sub-resolution feature in photoresist with an acceptable process latitude, said mask comprising:
- a layer of transparent material;
a layer of light-obstructing material; and
a layer of attenuating phase shifting material located between said layer of transparent material and said layer of light-obstructing material; and
wherein said layer of light-obstructing material and said layer of attenuating phase shifting material are patterned to form a transparent hole, a partially transmissive assist feature, and a light-obstructing frame located between said transparent hole and said partially transmissive assist feature.
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Accused Products
Abstract
A method of formulating and fabricating a mask pattern and resulting mask for forming isolated or closely spaced contact holes in an integrated circuit. The mask has a transparent mask substrate and patterned regions of attenuating phase shift material and opaque, partially transmissive or transparent material arranged to reduce the effect of side lobes and improve depth of focus. The rims, frames and outrigger patterns for the attenuating phase shift material and opaque, partially transmissive or transparent material are determined according to calculations performed on a processor with imaging software for various optical conditions and exposed feature criteria.
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Citations
48 Claims
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1. A microlithographic mask for forming a sub-resolution feature in photoresist with an acceptable process latitude, said mask comprising:
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a layer of transparent material;
a layer of light-obstructing material; and
a layer of attenuating phase shifting material located between said layer of transparent material and said layer of light-obstructing material; and
wherein said layer of light-obstructing material and said layer of attenuating phase shifting material are patterned to form a transparent hole, a partially transmissive assist feature, and a light-obstructing frame located between said transparent hole and said partially transmissive assist feature. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A mask for forming a contact hole with a depth of focus of at least 0.4 μ
- m, said mask comprising;
a first layer of material; and
a second layer of attenuating phase shifting material; and
wherein said first layer of material and said second layer of attenuating phase shifting material are patterned to form a transparent opening, a partially transmissive rim surrounding said opening, and sub-resolution assist features for preventing incident light from propagating through portions of said attenuating phase shifting material. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A microlithographic mask, comprising:
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transparent material; and
patterned opaque material and phase shifting material, said patterned materials defining an opening, an opaque frame surrounding said opening, sub-resolution bars surrounding said frame, and opaque corners located between sub-resolution bars. - View Dependent Claims (24, 25, 26, 27)
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28. A mask for forming an array of sub-resolution features, said mask comprising:
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a layer of transparent material;
a layer of light-obstructing material; and
a layer of attenuating phase shifting material located between said layer of transparent material and said layer of light-obstructing material; and
wherein said layer of light-obstructing material and said layer of attenuating phase shifting material are patterned to form transparent holes and light-obstructing frames surrounding said transparent holes. - View Dependent Claims (29, 30)
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31. A multi-tone mask for forming sub-resolution features, said mask comprising:
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a first layer of attenuating phase shifting material, said layer defining openings corresponding to said sub-resolution features; and
a second layer of material for preventing incident light from propagating through said first layer, said second layer including frames surrounding said openings, and wherein said second layer defines bar-shaped partially transmissive assist features. - View Dependent Claims (32)
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33. A mask for forming an elliptical feature in photoresist, said mask comprising:
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a layer of opaque material; and
a layer of attenuating phase shifting material located between said layer of transparent material and said layer of opaque material; and
wherein said layer of opaque material and said layer of attenuating phase shifting material are patterned to form transparent holes and opaque frames surrounding said transparent holes. - View Dependent Claims (34, 35, 36)
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37. A method of making a multi-tone microlithographic mask, said method comprising:
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providing sets of dimension data representative of mask patterns;
for each set of dimension data, calculating feature dimension data as a function of optical conditions; and
for a desired optical condition, identifying the sets of dimension data that have feature dimension data within desired limits. - View Dependent Claims (38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48)
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Specification