Method of determining defects in photomask

A method of determining defects in photomasks manufactured in a mask-manufacturing apparatus on the basis of mask-manufacturing data for manufacturing a plurality of masks, the method having:

• a step of preparing circuit data that represents a circuit to be formed on a semiconductor substrate by means of photolithography;
• a step of preparing layout data that has been developed from the circuit data and that represents the layout of a plurality of layers, which defines the circuit and which is to be formed on the semiconductor substrate, one above another;
• a step of preparing compensated layout data for the layers, by adding compensation data to the layout data representing the layout of the layers;
• and
• a step of preparing mask-manufacturing data that has been developed from the compensated layout data for the layers and that has been used to manufacture the masks for the layers,
• the method further comprising:
• a step of extracting patterns adaptive to active regions and non-active regions in order to form electrically active regions and electrically non-active regions when a certain pattern is formed by photolithography on the semiconductor substrate, in accordance with a connection-information table that describes a connection between circuit patterns represented by the layout data for the layers;
• a step of imparting attributes to all patterns represented by the mask-manufacturing data for manufacturing masks for the layers, the attributes showing whether the patterns are adaptive to active regions or non-active region;
• and
• a step of changing a criterion for determining whether the patterns formed on the photomasks have defects depending on whether each of the patterns correspond to an active region or a non-active region, in accordance with the attributes imparted to the patterns represented by the mask-manufacturing data for manufacturing masks for the layers.