Intel Corporation

Arvind Sundaramurthy

Charles Henry Wallace

Robert L Bristol

Swaminathan Sivakumar

Richard E Schenker

Tristan A Tronic

Shem Ogadhoh

Ryan Pearman

Guojing Zhang

John Magana

Sven Eric Henrichs

Chang Ju Choi

Embodiments described herein comprise extreme ultraviolet (EUV) reticles and methods of forming EUV reticles. In an embodiment, the reticle may comprise a substrate and a mirror layer over the substrate. In an embodiment, the mirror layer comprises a plurality of alternating first mirror layers and second mirror layers. In an embodiment, a phase-shift layer is formed over the mirror layer. In an embodiment, openings for printable features and openings for non-printable features are formed into the phase-shift layer. In an embodiment, the non-printable features have a dimension that is smaller than a dimension of the printable features.

EUV phase-shift SRAF masks by means of embedded phase shift layers

Techniques are disclosed for using sub-resolution phased assist features (SPAF) in a lithography mask to improve through process pattern fidelity and/or mitigate inverted aerial image problems. The technique also may be used to improve image contrast in non-inverted weak image sites. The use of SPAF in accordance with some such embodiments requires no adjustment to existing design rules, although adjustments can be made to enable compliance with mask inspection constraints. The use of SPAF also does not require changing existing fab or manufacturing processes, especially if such processes already comprehend phased shift mask capabilities. The SPAFs can be used to enhance aerial image contrast, without the SPAFs themselves printing. In addition, the SPAF phase etch depth can be optimized so as to make adjustments to a given predicted printed feature critical dimension.

Lithography mask having sub-resolution phased assist features

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Menlo Park, CA, United States of America

Arvind Sundaramurthy