A method for forming a mask pattern of a semiconductor device

A method for forming a mask pattern of a semiconductor device is provided to correct distortion of patterns due to optical proximity effect by using MDP(Mask Data Processing). A database of a design pattern is verified by using a design rule checker(S120). A first mask data process is performed to change the verified design pattern(S130). A model base OPC(Optical Proximity Correction) process is performed on the mask pattern after the first mask data process(S140). A correction process is performed by performing an optical rule checking process(S150). A mask data process is performed to correct a result value of a weak part after the optical rule checking process(S160).