Apparatus for treating substrate

An apparatus for treating a substrate, the apparatus comprising:

• a process chamber having a treatment space defined therein;
• a support plate for supporting the substrate in the treatment space;
• a fluid supply conduit for supplying supercritical fluid to the treatment space;
• a controller configured to control the fluid supply conduit,
• wherein the fluid supply conduit is configured to selectively supply the supercritical fluid at a first density or a second density higher than the first density into the treatment space;
• a reservoir for containing the supercritical fluid;
• a supply line for supplying the supercritical fluid contained in the reservoir to the treatment space;
• a first heater installed at the supply line and located downstream of the reservoir;
• a bypass line connected to the supply line and configured to bypass the first heater, the bypass line being connected to a main supply line at a first point and a second point;
• and
• an adjustment valve configured to allow the supercritical fluid to flow in a selected direction among a direction toward the bypass line and a direction toward the first heater,
• wherein the first point is located at upstream of the main supply line than the first heater,
• wherein the second point is located at downstream of the main supply line than the first heater, and
• wherein the first heater is located in the main supply line between the first point and the second point,
• wherein another heater is not installed on the bypass line.