US Patent 7691548 Method of manufacturing mask

There is provided a method of manufacturing a photomask for forming a semiconductor pattern. The method may include forming a plurality of dies including a main pattern, and forming a pseudo pattern to an area adjacent to the main pattern between the plurality of dies. A multi developing process of sequentially and repeatedly supplying a developer on the mask, supplying DI water on the mask, and drying the mask may be performed in manufacturing the mask.