Apparatus for drying wafer and method for drying wafer

A method for drying a wafer, comprising:

• supplying supercritical fluid to a drying chamber;
• stopping a supply of the supercritical fluid and drying a developer in the drying chamber;
• and
• exhausting the supercritical fluid from the drying chamber,
• wherein the exhausting the supercritical fluid comprises:
• exhausting the supercritical fluid through a main exhaust line connected to the drying chamber by opening a main valve, based on pressure of the drying chamber being above a first pressure,
• based on the pressure of the drying chamber decreasing to the first pressure, exhausting the supercritical fluid through a negative pressure tank installed in an auxiliary exhaust line by closing the main valve and opening a first valve and a second valve that are installed in the auxiliary exhaust line, and
• wherein a ratio of a pressure reduction amount in the drying chamber to an exhaust time of the supercritical fluid has an absolute value in a range of 0.75 to 9.0 bar/sec, in a case where the supercritical fluid is exhausted through the negative pressure tank installed in the auxiliary exhaust line.