Intel Corporation

Eng T Gaw

Giang T Dao

Nelson N Tam

Harry H Fujimoto

Qi De Qian

Ian A Young

Chien Chiang

David B Fraser

Quat T Vu

Kenny K Toh

Ruben A Rodriquez

Rajeev R Singh

Thomas N D Marieb

A reduced capacitance interconnect system. A first metal layer is formed to a predetermined level above a first dielectric layer which is formed on a semiconductor substrate. The first metal layer level forms multiple interconnect lines wherein each interconnect line is separated from each adjacent interconnect line by a trench including a trench having a highest aspect ratio. A second dielectric layer is formed on the first metal layer and in the trenches between the interconnect lines such that an enclosed void having a void tip substantially level with the top of the metal layer is formed in at least each trench having an aspect ratio above a predetermined minimum aspect ratio, wherein the enclosed void in the trench having the highest aspect ratio has a void volume which is at least 15% of the volume of the trench.

Method and structure for reducing interconnect system capacitance through enclosed voids in a dielectric layer

Methods of forming a patterned layer using a reticle having a phase-shifting element and the reticles for making the patterns are disclosed. The methods of the present invention use a phase-shifting element to change the phase of the radiation exiting a reticle about 180.degree. out of phase compared to the radiation exiting the areas immediately adjacent to an edge of the phase-shifting element so that radiation from both areas near the edge destructively interfere with each other so as to cancel out one another thereby resulting in a substantially unexposed region on a semiconductor substrate. The present invention can be used to prevent exposing a large area by using a set of phase-shifting elements to form a grating or checkerboard area.

Lithography using a new phase-shifting reticle

A phase-shifted reticle with patterns proximate each other having inverted phases for the features and phase-shifting elements, and method of fabricating the reticle. Each of the patterns and inverted patterns are structurally identical with regard to the direction of phase shift, so that any focal shift due to phase error is in the same direction for all patterns. In a preferred embodiment, the structurally identical inverted reticle is used to form an array of closely spaced contact or via openings. For a first pattern on the reticle, the feature will be the 0.degree. phase and the phase-shifting rim surrounding that feature will be the 180.degree. phase. All patterns surrounding the first pattern have phase-shifting rims of the 0.degree. phase and features of the 180.degree. phase. In this way, each pattern can form below conventional resolution features in the resist. Additionally, there will not be exposure of the regions between the closely spaced features since radiation transmitted through the closely spaced phase-shifting rims of the two patterns is 180.degree. out of phase. Also, since each pattern is structurally identical, any focal shift due to phase error is in the same direction for all patterns, so that an acceptable depth of field is maintained for a substrate exposed with the reticle.

Reticle with structurally identical inverted phase-shifted features

A phase-shifted reticle with patterns proximate each other having inverted phases for the features and phase-shifting elements, and methods of fabricating the reticle. Each of the patterns and inverted patterns are structurally identical with regard to the direction of phase shift, so that any focal shift due to phase error is in the same direction for all patterns. In a preferred embodiment, the structurally identical inverted reticle is used to form an array of closely spaced contact or via openings. For a first pattern on the reticle, the feature will be the 0.degree. phase and the phase-shifting rim surrounding that feature will be the 180.degree. phase. All patterns surrounding the first pattern have phase-shifting rims of the 0.degree. phase and features of the 180.degree. phase. In this way, each pattern can form below conventional resolution features in the resist. Additionally, there will not be exposure of the regions between the closely spaced features since radiation transmitted through the closely spaced phase-shifting rims of the two patterns is 180.degree. out of phase. Also, since each pattern is structurally identical, any focal shift due to phase error is in the same direction for all patterns, so that an acceptable depth of field is maintained for a substrate exposed with the reticle.

A phase-shifted reticle with patterns proximate each other having inverted phases for the features and phase-shifting elements, and methods of fabricating the reticle, are disclosed. In a preferred embodiment, the inverted reticle is used to form an array of closely spaced contact or via openings. For a first pattern on the reticle, the feature will be the 0.degree. phase and the phase-shifting rim surrounding that feature will be the 180.degree. phase. All patterns surrounding the first pattern have phase-shifting rims of the 0.degree. phase and features of the 180.degree. phase. In this way, each pattern can form below conventional resolution features in the resist. Additionally, there will not be exposure of the regions between the closely spaced features since radiation transmitted through the closely spaced phase-shifting rims of the two patterns is 180.degree. out of phase.

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San Jose, CA, United States of America

Eng T Gaw