Abstract: A baffle is placed in a position opposed to discharge openings of a treating solution supply nozzle and between the discharge openings and the surface of a substrate. The baffle intercepts a treating solution discharged from the discharge openings, whereby the treating solution is supplied evenly to the surface of the substrate by flowing over a surface of the baffle and falling from an edge of the baffle to the substrate, instead of falling from the discharge openings directly to the substrate. No microbubbles are formed in the treating solution on the substrate, which would cause an unevenness of treatment. The discharge openings may be defined by a plurality of circular bores formed in the supply nozzle. Each circular bore may have a diameter at least equal to a spacing between an adjacent pair of circular bores.

Abstract: A substrate spin coating apparatus for forming a coating film on the upper surface of a spinning substrate includes a spin chuck for supporting and spinning the substrate while holding same substantially in horizontal posture. A scatter preventive cup surrounds lateral and lower regions of the spin chuck, and defines an opening in an upper central region thereof for allowing entry of air flows. An exhaust vent is provided for downwardly exhausting the air flows, and a nozzle is provided for supplying a coating solution through the opening of the scatter preventive cup to the upper surface of the substrate. The scatter preventive cup includes an air passage formed in a bottom region thereof and opening toward a lower surface of the substrate. An air flow adjusting unit is connected to the air passage for adjusting an air flow to a predetermined temperature and supplying the adjusted air flow to the air passage.