1. A method for generating a pattern, comprising: reading out an interconnect layout and a hole layout, the interconnect layout prescribing a plurality of interconnect patterns, the hole layout prescribing a plurality of hole patterns configured to connect to the interconnect patterns; extracting one of the hole patterns to be connected within the same interconnect layer level to one of the interconnect patterns in a pattern processing area; extracting a first processing area including the extracted hole pattern; calculating a first pattern density of the interconnect patterns included in the first processing area; and generating first additional patterns in the first processing area based on the first pattern density.