Numerical Technologies, Inc.

Synopsys, Inc.

Seonghun Cho

Shao-Po Wu

Yao-Ting Wang

Alexandre Arkhipov

Ilya Henry Grishashvili

Yu-Yu Chou

A method of assigning phases to shifters on a layout is provided. The method includes creating a link between any two shifters within a predetermined distance from each other. In one embodiment, the predetermined distance is larger than a minimum feature size on the layout, and smaller than a combined minimum pitch and regulator width. A weight can be assigned to each created link. Phases can be assigned to the shifters, wherein if a phase-shift conflict exists on the layout, then one or more links can be broken based on their weight.

Resolving phase-shift conflicts in layouts using weighted links between phase shifters

One embodiment of the invention provides a system that automatically resolves conflicts between phase shifters during creation of a phase shifting mask to be used in an optical lithography process for manufacturing an integrated circuit. Upon receiving a specification of a layout on the integrated circuit, the system identifies critical-dimension features within the layout. Next, the system places phase shifters comprised of phase shifting geometries on the phase shifting mask to precisely define the critical-dimension features. In doing so, the system identifies junctions within and/or between the critical-dimension features, and removes phase shifting geometries associated with the junctions to obviate coloring conflicts between phase shifters on the phase shifting mask. In one embodiment of the invention, the junctions include T-junctions and/or L-junctions.

Method and apparatus for resolving coloring conflicts between phase shifters

One embodiment of the invention provides a method that facilitates selectively varying how much of a layout of an integrated circuit is defined by phase shifters during an optical lithography process used in manufacturing the integrated circuit. During operation, the method receives a specification of the layout of the integrated circuit. The method then assigns features within the layout to zones associated with different phase shifting priorities. Next, the method generates a phase shifter placement by placing phase shifters comprised of phase shifting geometries onto a phase shifting mask to define the features within the layout, wherein the phase shifter placement is subject to coloring constraints. Note that in general there is no restriction on the order of zone placement. During this placement process, if coloring constraints cannot be satisfied, the method resolves conflicts and/or removes features from being phase-shifted based upon phase shifting priorities of the zones.

Facilitating an adjustable level of phase shifting during an optical lithography process for manufacturing an integrated circuit

One embodiment of the invention provides a system for generating trim to be used in conjunction with phase shifters during an optical lithography process for manufacturing an integrated circuit. The system operates by identifying a feature within the integrated circuit to be created by using a phase shifter to produce a region of destructive light interference on a photoresist layer. Next, the system generates the phase shifter for a first mask, while ensuring that design rules are satisfied in defining dimensions for the phase shifter. After the phase shifter is generated, the system generates trim within a second mask, that is used in conjunction with the first mask, by deriving the trim from the previously-defined dimensions of the phase shifter while ensuring that the design rules are satisfied. Note that the design rules can be satisfied by cutting and/or patching portions of the phase shifter and associated trim.

Method and apparatus for reducing color conflicts during trim generation for phase shifters

One embodiment of the invention provides a method and a system for using phase shifter cutbacks to resolve conflicts between phase shifters during creation of a mask to be used in an optical lithography process for manufacturing an integrated circuit. The system works by locating a plurality of phase shifters, including a first phase shifter and a second phase shifter, on a phase shifting mask, and then identifying a conflict area wherein a conflict is likely to occur between the first phase shifter and the second phase shifter on the phase shifting mask. The system resolves this conflict by cutting back one or both of the first phase shifter and the second phase shifter, so that the first phase shifter and the second phase shifter do not interfere with each other in the conflict area.

Growing community of inventors

Santa Clara, CA, United States of America

Seonghun Cho