Pattern matching method

A pattern matching method comprising:

• generating an image of a first region in a pattern region containing patterns formed by multi-patterning;
• performing first matching between a plurality of reference patterns on the image of the first region and a plurality of first CAD patterns that have been classified in advance into a first group and a second group according to layer information;
• classifying the plurality of reference patterns into the first group and the second group according to the layer classification of the first CAD patterns;
• calculating slopes of brightness profiles of edges of the plurality of reference patterns belonging to the first group and slopes of brightness profiles of edges of the plurality of reference patterns belonging to the second group;
• determining a first integrated value by integrating calculated values of the slopes of the brightness profiles of the edges of the plurality of reference patterns belonging to the first group;
• determining a second integrated value by integrating calculated values of the slopes of the brightness profiles of the edges of the plurality of reference patterns belonging to the second group;
• determining a magnitude relationship between the first integrated value and the second integrated value;
• generating an image of a second region in the pattern region;
• performing second matching between a plurality of patterns on the image of the second region and a plurality of second CAD patterns that have been classified in advance into a first group and a second group according to layer information;
• classifying the plurality of patterns on the image of the second region into the first group and the second group according to the layer classification of the second CAD patterns;
• calculating slopes of brightness profiles of edges of the plurality of patterns belonging to the first group and slopes of brightness profiles of edges of the plurality of patterns belonging to the second group;
• determining a third integrated value by integrating calculated values of the slopes of the brightness profiles of the edges of the plurality of patterns belonging to the first group;
• determining a fourth integrated value by integrating calculated values of the slopes of the brightness profiles of the edges of the plurality of patterns belonging to the second group;
• determining a magnitude relationship between the third integrated value and the fourth integrated value;
• determining that the second matching has been performed correctly when the magnitude relationship between the third integrated value and the fourth integrated value coincides with the magnitude relationship between the first integrated value and the second integrated value.