Patent ID: 7996794

Claim:
A mask data processing method for generating mask data related to design data having a hierarchical data structure using a computer, the method comprising: forming the hierarchical data structure, the hierarchical data structure including cells blocks defined by the design data including patterns and critical cell patterns, the critical cell patterns having a width smaller than a predetermined value, and a number of repetitions of the patterns and critical cell patterns; correcting the design data to create corrected design data, the corrected design data including at least one new cell block including at least one of the cell blocks based on recommended cell structure indices, the indices being a value greater than or equal to the width of the critical cell pattern and a number of repetitions of a cell forming a part of at least one cell block; restructuring the hierarchical data structure based on corrected design data including the at least one new cell block; wherein restructuring the hierarchical data structure further includes restructuring based on the number of different patterns and critical cell patterns included in the design data, a total edge length of repeated cell blocks on an edge along the repeated cell blocks included in the design data, a calculation amount associated with the critical cell patterns, or an expansion degree of the at least one new cell block, using a hierarchical data structure correction program stored in a memory in the computer.