Stiction-free microstructure releasing method for fabricating MEMS device

A method for releasing a microstructure for fabricating a device of a micro electro mechanical system (MEMS), comprising:

• supplying bubbled alcohol vapor as a catalyst with anhydrous HF;
• maintaining a temperature of the supplying device and a moving path of the anhydrous HF and the alcohol to be higher than a boiling point of the alcohol;
• performing a vapor etching by controlling a temperature and a pressure to be within the vapor region of a phase equilibrium diagram of water, thereby
• removing silicon oxide of a sacrificial layer on a lower portion of the microstructure,
• wherein the vapor etching is performed under a total pressure of an etching chamber ranged from about 25 torr to about 75 torr and a temperature of a substrate ranged from about 25° C. to about 75° C., and a temperature inside of the etching chamber is maintained to be higher than that of the substrate so as to discharge the water generated during the vapor etching without condensation.