Supercritical drying method for semiconductor substrate

A supercritical drying method for a semiconductor substrate, comprising:

• cleaning the semiconductor substrate with a chemical solution;
• rinsing the semiconductor substrate with pure water to cover a surface of the semiconductor substrate with the pure water after the cleaning;
• supplying a water soluble organic solvent onto the semiconductor substrate after the rinsing, to replace the pure water covering the surface of the semiconductor substrate with the water soluble organic solvent;
• introducing the semiconductor substrate into a chamber, the surface of the semiconductor substrate being covered with the water soluble organic solvent;
• increasing a temperature inside of the chamber up to a critical temperature of the water soluble organic solvent or higher, to turn the water soluble organic solvent into a supercritical state;
• after turning the water soluble organic solvent into the supercritical state, increasing a temperature inside of the chamber to turn pure water in the chamber into steam while maintaining the water soluble organic solvent in the supercritical state;
• and
• decreasing a pressure inside of the chamber while keeping a temperature inside of the chamber at a predetermined value at which the steam is not liquefied, to turn the water soluble organic solvent in the supercritical state into a gaseous state, thus discharging the water soluble organic solvent from the chamber.