Apparatus for drying wafer and method for drying wafer

An apparatus for drying a wafer, comprising:

• a drying chamber having an interior space;
• a supercritical fluid supply module connected to the drying chamber and configured to supply supercritical fluid to the drying chamber;
• a main exhaust line connected to the drying chamber and in which a main valve is installed;
• and
• an auxiliary exhaust unit connected to the main exhaust line,
• wherein the supercritical fluid supply module comprises:
• a fluid storage tank;
• a condenser connected to the fluid storage tank and configured to pressurize fluid;
• a pump disposed at a rear end of the condenser;
• a reservoir tank disposed at a rear end of the pump and configured to store the fluid pressurized by the condenser;
• and
• a heater disposed at a rear end of the reservoir tank and configured to heat the fluid,
• wherein the auxiliary exhaust unit comprises:
• an auxiliary exhaust line connected to the main exhaust line and configured to exhaust the supercritical fluid from the drying chamber when the main valve is closed;
• a negative pressure tank installed in the auxiliary exhaust line;
• a first valve, installed in the auxiliary exhaust line, that is disposed at a front end of the negative pressure tank and configured to be opened when the main valve is closed;
• and
• a second valve, installed in the auxiliary exhaust line, that is disposed at a rear end of the negative pressure tank and configured to be opened in conjunction with the first valve,
• wherein a ratio of a pressure reduction amount in the drying chamber to an exhaust time of the supercritical fluid through the auxiliary exhaust unit, when internal pressure of the drying chamber is equal to or lower than a first pressure, has an absolute value within a range of 0.75 to 9.0 bar/sec.