A method for making a mask in a process of fabricating a semiconductor device is disclosed, in which one database is classified into an SRAM block and a random logic block so that OPC is separately performed for the SRAM block and the random logic block, thereby improving performance of the OPC. The method includes dividing an input database into an SRAM block and a random logic block, respectively performing optical proximity correction (OPC) for the SRAM block and the random logic block, and combining the SRAM block to the random logic block.