Optical proximity correction for mask repair

A method for repairing mask defects in a photomask, comprising:

• providing a photomask with a mask pattern for an integrated circuit (IC);
• receiving an aerial image and a diffraction image of the photomask from an optical microscope system;
• performing inverse image rendering on the aerial image by applying an optical model that divides an incoherent exposure source into a plurality of coherent sources, wherein the optical model comprises calculations that generate a simulated aerial image from the aerial image and the diffraction image of the photomask;
• determining mask defects by comparing from a design layout of the IC and the simulated aerial image;
• and
• repairing the mask defects on the photomask.

A method for repairing mask defects in a photomask, comprising:

• receiving a design layout for an integrated circuit;
• forming a mask pattern on a photomask;
• acquiring, by an optical microscope system, an aerial image of the photomask;
• applying an optical model that divides an incoherent exposure source into a plurality of coherent sources, wherein the optical model generates a simulated image of the mask pattern and a simulated aerial image from the aerial image of the photomask, wherein the simulated image of the mask pattern is a function of light field of illumination of a microscope condenser, polarization decomposition, transfer function of microscope pupil, and light field through mask;
• extracting mask defects by comparing the design layout and the simulated aerial image;
• and
• repairing the mask defects.