System and method for correcting 3D effects in an alternating phase-shifting mask

A library used for creating an alternating phase-shifting mask that compensates for three dimensional effects, the library comprising:

• a plurality of original sizes for 180 degree phase-shifting regions on the alternating phase-shifting mask;
• a plurality of pre-corrected sizes;
• a plurality of transmission values;
• and
• a plurality of phase values, wherein each original size has a corresponding pre-corrected size, a corresponding transmission value, and a corresponding phase value, and wherein the corresponding transmission value and the corresponding phase value allow a two dimensional simulation for the corresponding pre-corrected size to substantially match a three dimensional simulation for the original size.

A method of designing a lithographic mask, the method comprising:

• placing 0 degree phase-shifting regions and 180 degree phase-shifting regions on the lithographic mask;
• accessing a library of pre-corrected shifters, wherein each pre-corrected shifter references a size of an original 180 degree phase-shifting region and matching 3D simulation information;
• and
• replacing any 180 degree phase-shifting region with a pre-corrected shifter if that 180 degree phase-shifting region has a size referenced in the library.

A method of performing optical proximity correction (OPC) on a layout for an alternating phase-shifting mask, the method comprising:

• identifying a first phase-shifting region and a second phase-shifting region on the layout, wherein a difference between the first phase-shifting region and the second phase-shifting region is approximately 180 degrees, and wherein the second phase-shifting region creates three dimensional effects on the alternating phase-shifting mask;
• accessing a library of pre-corrected shifters, wherein each pre-corrected shifter references a size of an original 180 degree phase-shifting region and matching simulation information;
• replacing the second phase-shifting region with a pre-corrected shifter if a size of the second phase-shifting region is provided in the library;
• and
• performing the OPC on the pre-corrected shifter.

A computer program product for creating an alternating phase-shifting mask, the computer program product comprising:

• a first set of instructions for determining a first group of 180 degree phase-shifting regions for the alternating phase-shifting mask, the first group of 180 degree phase-shifting regions having a common first size;
• a second set of instructions for performing a three-dimensional (3D) simulation based on the first size;
• a third set of instructions for performing a two-dimensional (2D) simulation based on the first size;
• a fourth set of instructions for altering a transmission and a phase in the 2D simulation until a shape dependent transmission and a shape dependent phase allow the 2D simulation to substantially match the 3D simulation;
• a fifth set of instructions for choosing a modified first size of a 180 degree phase-shifting region using the shape dependent transmission and the shape dependent phase such that a 2D simulation based on the modified first size substantially matches the 3D simulation based on the first size;
• and
• a sixth set of instructions for associating the first size, the modified first size, the shape dependent transmission, and the shape dependent phase.

A lithographic mask that provides phase-shifting for features on a binary mask, the lithographic mask comprising:

• a plurality of first phase-shifting regions;
• and
• a plurality of second phase-shifting regions,
• wherein each first phase-shifting region has a corresponding second phase-shifting region,
• wherein a phase difference between the first and second phase-shifting regions is approximately 180 degrees,
• wherein each second phase-shifting region has a size based on a size of its corresponding first phase-shifting region.

An apparatus for compensating for three dimensional effects on an alternating phase-shifting mask, the apparatus comprising:

• means for receiving an input file including a layout of the alternating phase-shifting mask;
• means for identifying a first phase-shifting region and a second phase-shifting region on the layout, wherein a difference between the first phase-shifting region and the second phase-shifting region is approximately 180 degrees, and wherein the second phase-shifting region creates the three dimensional effects;
• means for accessing a memory including a library of pre-corrected shifters, wherein each pre-corrected shifter references a size of an original second phase-shifting region and matching simulation information;
• and
• means for replacing the second phase-shifting region with a pre-corrected shifter if a size of the second phase-shifting region is provided in the library, thereby compensating for the three dimensional effects.

A system for compensating for three dimensional effects on an alternating phase-shifting mask, the system comprising:

• an input interface for receiving a layout of the alternating phase-shifting mask;
• an output interface for providing a modified layout that compensates for the three-dimensional effects;
• a memory comprising:
• a library including:
• a plurality of original sizes for 180 degree phase-shifting regions on the alternating phase-shifting mask;
• a plurality of pre-corrected sizes;
• a plurality of transmission values;
• and
• a plurality of phase values, wherein each original size has a corresponding pre-corrected size, a corresponding transmission value, and a corresponding phase value, and wherein the corresponding transmission value and the corresponding phase value allow a two dimensional simulation for the corresponding pre-corrected size to substantially match a three dimensional simulation for the original size;
• a plurality of computer-implemented programs for generating the corresponding pre-corrected size, transmission value, and phase value;
• and
• a processor for executing the plurality of computer-implemented programs.

A method of designing a trim mask and an associated phase-shifting mask, the method comprising:

• placing 0 degree phase-shifting regions and 180 degree phase-shifting regions on the phase-shifting mask;
• accessing a library of pre-corrected shifters, wherein each pre-corrected shifter references a size of an original 180 degree phase-shifting region, at least one transmission, and at least one phase, wherein by using the at least one transmission and the at least one phase, a two-dimensional simulation of the pre-corrected shifter substantially matches a three-dimensional simulation of the original 180 degree phase-shifting region;
• performing optical proximity correction (OPC) on a feature on the trim mask using the at least one transmission and the at least one phase of an associated 180 degree phase-shifting region;
• and
• extending an area of the associated 180 degree phase-shifting region on the phase-shifting mask to be in operative position with the feature.