Patent ID: 11819872

Abstract:
A substrate processing apparatus includes a rotational holding member that rotates a substrate around a predetermined rotational axis while holding the substrate, a liquid supply member that supplies a liquid to the substrate held by the rotational holding member, and a resin-made tubular guard that surrounds the substrate held by the rotational holding member. The tubular guard has an inner peripheral surface and an uneven portion disposed at the inner peripheral surface. The uneven portion has a plurality of recessed portions and a plurality of protruding portions placed between the recessed portions adjacent to each other. The recessed portion has a width smaller than a diameter of a liquid droplet scattering from the substrate held by the rotational holding member and a depth in which the liquid droplet does not come into contact with a bottom portion of the recessed portion in a state in which the liquid droplet is in contact with the protruding portions. The protruding portion has a width that is smaller than the diameter of the liquid droplet and that is smaller than the width of the recessed portion.