Method for forming epitaxial layer at low temperature

Provided is a method for forming an epitaxial layer at a low temperature. The method for forming the epitaxial layer includes transferring a substrate into an epitaxial chamber and performing an epitaxial process on the substrate to form an epitaxial layer on the substrate. The epitaxial process includes heating the substrate at a temperature of about 700° C. or less and injecting a silicon gas into the epitaxial chamber in a state in which the inside of the epitaxial chamber is adjusted to a pressure of about 300 Torr or less to form a first epitaxial layer, stopping the injection of the silicon gas and injecting a purge gas into the epitaxial chamber to perform first purge inside the epitaxial chamber, heating the substrate at a temperature of about 700° C. or less and injecting the silicon gas into the epitaxial chamber in the state in which the inside of the epitaxial chamber is adjusted to a pressure of about 300 Torr or less to form a second epitaxial layer, and stopping the injection of the silicon gas and injecting the purge gas into the epitaxial chamber to perform second purge inside the epitaxial chamber.