Globalfoundries Inc.

Globalfoundries U.S. Inc.

Kla Corporation

Minghao Tang

Dongyue Yang

Rui Chen

Xintuo Dai

Md Motasim Bellah

Pavan Kumar Chinthamanipeta Sripadarao

Dongsuk Park

Cheuk Wun Wong

Cung D Tran

Ravi Prakash Srivastava

Yuping Ren

Sanggil Bae

Bradley Morgenfeld

Christian J Ayala

Kripa Nidhan Chauhan

Huaxiang Li

Haiting Wang

Scott Beasor

Sean Xuan Lin

Shao Beng Law

Wei Zhao

Genevieve Beique

Erik Geiss

Xun Xiang

Two pairs of alignment targets (one aligned, one misaligned by a bias distance) are formed on different masks to produce a first pair of conjugated interference patterns. Other pairs of alignment targets are also formed on the masks to produce a second pair of conjugated interference patterns that are inverted the first. Misalignment of the dark and light regions of first interference patterns and the second interference patterns in both pairs of conjugated interference patterns is determined when patterns formed using the masks are overlaid. A magnification factor (of the interference pattern misalignment to the target misalignment) is calculated as a ratio of the difference of misalignment of the relatively dark and relatively light regions in the pairs of interference patterns, over twice the bias distance. The interference pattern misalignment is divided by the magnification factor to produce a self-referenced and self-calibrated target misalignment amount, which is then output.

Self-referencing and self-calibrating interference pattern overlay measurement

Two pairs of alignment targets (one aligned, one misaligned by a bias distance) are formed on different masks to produce a first pair of conjugated interference patterns. Other pairs of alignment targets are also formed on the masks to produce a second pair of conjugated interference patterns that are inverted the first. Misalignment of the dark and light regions of the first interference patterns and the second interference patterns in both pairs of conjugated interference patterns is determined when patterns formed using the masks are overlaid. A magnification factor (of the interference pattern misalignment to the target misalignment) is calculated as a ratio of the difference of misalignment of the relatively dark and relatively light regions in the pairs of interference patterns, over twice the bias distance. The interference pattern misalignment is divided by the magnification factor to produce a self-referenced and self-calibrated target misalignment amount, which is then output.

In an exemplary method, a first layer is formed on a substrate. First overlay marks are formed in a first zone of the first layer. A non-transparent layer is formed on top of the first layer. At least a portion of the non-transparent layer is removed from an area above the first zone of the first layer. This provides optical access to the first overlay marks. A second layer is formed on top of the non-transparent layer. Second overlay marks are formed in a second zone of the second layer. Position information is obtained from each of the first overlay marks and the second overlay marks.

Structure and method to improve overlay performance in semiconductor devices

One illustrative example of an overlay mark disclosed herein includes four quadrants (I-IV). Each quadrant of the mark contains an inner periodic structure and an outer periodic structure. Each of the outer periodic structures includes a plurality of outer features. Each of the inner periodic structures includes a plurality of first inner groups, each of the first inner groups having a plurality of first inner features, each first inner group being oriented such that there is an end-to-end spacing relationship between each first inner group and a selected one of the outer features.

Asymmetric overlay mark for overlay measurement

Methods of self-aligned multiple patterning. A mandrel line is formed over a hardmask layer, and forming a block mask is formed over a first portion of the mandrel line that is linearly arranged between respective second portions of the mandrel line. After forming the first block mask, the second portions of the mandrel line are removed with an etching process to cut the mandrel line and expose respective portions of the hardmask layer. A second portion of the mandrel line is covered by the block mask during the etching process to define a mandrel cut in the mandrel line.

Multiple patterning with mandrel cuts formed using a block mask

Methods of fabricating an interconnect structure. A first sacrificial layer is deposited over a dielectric layer, and a block mask is formed that covers an area on the first sacrificial layer. A second sacrificial layer is deposited over the block mask and the first sacrificial layer. After the block mask is formed, the second sacrificial layer is patterned to form a mandrel that is arranged in part on a portion of the block mask.

Interconnects with cuts formed by block patterning

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Ballston Lake, NY, United States of America

Minghao Tang