Suppressing specular reflection of mask absorber and on- resolution field stitching

A method for generating a mask pattern design for use in imaging of a pattern on a substrate using a lithographic apparatus, the method comprising:

• determining a pitch of a sub-resolution feature to be placed in an area of an absorber layer of the mask pattern design based on a parameter of an illumination for a lithographic apparatus;
• adjusting, by a hardware computer system, a duty cycle of the sub-resolution feature to achieve a prescribed background intensity criterion;
• and
• determining, by the hardware computer system, a placement of the sub-resolution feature in the area of the absorber layer located between two adjacent exposure fields in a lithography process.

A non-transitory computer-readable medium having instructions therein, the instructions, when executed by a computer system, configured to cause the computer system to at least:

• determine, based on a parameter of an illumination for a lithographic apparatus, a pitch of a sub-resolution feature to be placed in an area of an absorber layer of a mask pattern design for use in imaging of a pattern on a substrate using the lithographic apparatus;
• adjust the sub-resolution feature to achieve a prescribed background intensity criterion;
• and
• determine a placement of the sub-resolution feature in the area of the absorber layer located between two adjacent exposure fields in a lithography process.