Substrate support and substrate processing apparatus

A substrate support comprising:

• a base electrically connected to at least one power supply;
• a first dielectric disposed on the base and having a substrate support surface;
• and
• a second dielectric disposed on the base to surround the first dielectric and having a ring support surface,
• wherein the first dielectric comprises:
• a first heat transfer gas diffusion space configured to supply a heat transfer gas toward the substrate support surface;
• a first electrode disposed above the first heat transfer gas diffusion space to vertically overlap with at least a part of the first heat transfer gas diffusion space;
• and
• a conductor that electrically connects the first electrode and the base, and wherein the second dielectric comprises:
• a second heat transfer gas diffusion space configured to supply a heat transfer gas toward the ring support surface;
• and
• a second electrode disposed above the second heat transfer gas diffusion space to vertically overlap with at least a part of the second heat transfer gas diffusion space, and electrically connected to a power supply that outputs a common voltage with the base.