PURPOSE: To obtain an epitaxial layer having small defect density and consisting of excellent silicon by applying a high-frequency electric field to the mixed gas of an inert gas and an etching gas to generate ion radicals, sputtering the surface of a base and growing the surface of the base in an epitaxial manner.
CONSTITUTION: A mixed gas containing SF6 gas as an etching gas in Ar gas as an inert gas is introduced from a gas introducing pipe 2, evacuating the inside of a reaction pipe 1 from an exhaust pipe 3. When a coil 9 is supplied with high frequency from a high-frequency power supply 10, Ar gas is ionized, and F ion radicals are generated. Since Ar ions and F ion radicals are made to collide with a substrate surface, a natural oxide film is removed through sputtering, an silicon substrate is etched, and a clean substrate surface is exposed. SiH4 gas is introduced into the reaction pipe 1 from the introducing pipe 2, and an silicon single crystal is grown in an epitaxial manner by the thermal decomposition of SiH4 gas under decompression.