Patent ID: 7674561

Claim:
A method of producing a mask blank, the method comprising: a resist film forming process of dispensing a resist solution containing a resist material and a solvent onto a substrate that is substantially square in shape, rotating the substrate to spread the dispensed resist solution over the substrate, and drying the resist solution spread on the substrate, thereby forming a resist film on the substrate, wherein: during the rotating step, a puddle of the resist solution is formed at an outer peripheral portion of the substrate while the substrate is rotated in the resist film forming process, the resist solution having a viscosity such that the puddle is drawn back towards a center of the substrate during the rotation of the substrate, and an airflow is produced along an upper surface of the substrate from the center of the substrate towards the outer peripheral portion of the substrate, and is controlled in velocity and direction so as to suppress the puddle from moving towards the center because of the viscosity of the resist solution during the rotation of the substrate, and wherein the resist film forming process includes a primary stage for rotating the substrate at a first rotation speed and a secondary stage for rotating the substrate at a second rotation speed lower than the first rotation speed.