| abstract |
(57) [Summary] [Object] To clean a surface of a semiconductor substrate, to provide a method capable of obtaining a highly flat and contaminant-free surface by first removing a native oxide film. [Structure] A semiconductor substrate is placed in a reaction chamber, a hydrofluoric acid gas is introduced to remove a natural oxide film, and then chlorine fluoride gas is introduced, and ultraviolet rays are irradiated to perform etching. It is introduced and irradiated with ultraviolet rays to remove chloride. |