Patent ID: 8277884

Claim:
A method of spin coating a coating solution on a quadrangular mask substrate used in exposure processing of a photolithographic process and removing a coating solution undesirably attached to a back surface and a side surface of the substrate by a rinse liquid, comprising the steps of: (p1) preparing a spin chuck comprising a cover having a rinse liquid collection portion, a coating solution nozzle, a rinse liquid nozzle, a pair of spacers mounted on the spin chuck, a holding plate having a top surface being provided with liquid flow guide members that control a direction of flow of the rinse liquid toward the corner portions, and a guide channel opening at a position corresponding to each of corner portions of the substrate on the holding plate and communicating with the rinse liquid collection portion; (a) supporting the back surface of the substrate by substrate supporting members while slightly separating upward from the surface of the holding plate, and positioning the substrate to the spin chuck by the pair of spacers thereby holding the substrate horizontally with the holding plate provided on the spin chuck by a periphery of the substrate, with a clearance between the substrate and the holding plate; (b) supplying the coating solution from the coating solution nozzle to a surface of the substrate held by the spin chuck and spreading the coating solution with the help of centrifugal force by rotating the spin chuck around a vertical axis; and (c) supplying the rinse liquid to the clearance to reach the back surface of the substrate from the rinse liquid nozzle while rotating the holding plate synchronously with a substrate around the vertical axis, and supplying the rinse liquid through the rinse liquid collection portion and the guide channel serving as a rinse liquid supply port formed at a position of the holding plate corresponding to each of the corner portions of the substrate, thereby permitting the rinse liquid to reach the corner portions of the substrate with the help of centrifugal force to wash away the coating solution.