Substrate treating apparatus and substrate treating method

An apparatus for treating a substrate, the apparatus comprising:

• a processing vessel having a processing space;
• a support unit for supporting the substrate in the processing space and rotating the substrate;
• a liquid supply unit for supplying a processing liquid to the substrate supported by the support unit;
• and
• a heating unit for heating the substrate,
• wherein the support unit includes:
• a spin chuck;
• a rotation driver for rotating the spin chuck;
• a chuck pin installed on the spin chuck so as to be rotated together with the spin chuck;
• and
• a chuck pin moving unit including a cam ring, a cam ring driver for rotating the cam ring, and a slip-ring assembly for providing power to the cam ring driver, wherein the chuck pin moving unit is configured for moving the chuck pin between a contact position at which the chuck pin is in contact with a side portion of the substrate and an open position at which the chuck pin is spaced apart from the side portion of the substrate, and
• the chuck pin moving unit moves the chuck pin while the substrate is rotated by the spin chuck.