Substrate treating apparatus and substrate support unit

A substrate support unit for supporting a substrate, the substrate support unit comprising:

• an upper plate;
• and
• a lower plate provided under the upper plate,
• wherein a first gap is formed between the upper plate and the lower plate, and
• wherein the substrate support unit further includes a supply pipe configured to supply a gas into a space formed by the first gap while passing through the lower plate.

A substrate treating apparatus for treating a substrate by using plasma, the apparatus comprising:

• a process chamber configured to form a treatment space;
• a gas supply unit configured to supply a process gas into an interior of the process chamber;
• a plasma generating unit configured to generate plasma from the process gas introduced into the interior of the process chamber;
• and
• a substrate support unit provided in the treatment space and configured to support the substrate,
• wherein the substrate support unit includes:
• a dielectric plate in which an electrostatic electrode is embedded and is configured to suction the substrate;
• an electrode plate provided under the dielectric plate and having a passage, through which a coolant flows, in the interior thereof;
• an annular focus ring provided at a circumference of the dielectric plate;
• an insulator plate provided under the electrode plate and formed of an insulator;
• a base plate provided under the insulator plate and grounded,
• wherein a gap is formed at at least one of locations between the electrode plate and the insulator plate and between the insulator plate and the base plate;
• and
• a supply pipe connected to the gap and configured to supply dry air or an inert gas to the gap.