PURPOSE: To provide a method for preventing generation of rosettes (defects) or reducing the number of rosettes (defects) as compared with that of prior art when antimony is used as impurity and an impurity diffused layer is formed on a silicon substrate.

CONSTITUTION: A silicon oxide film 43 is formed on a surface of a silicon substrate 41. An opening 43a is selectively formed on the film 42. Antimony is introduced from above the oxide film formed with the opening 43a to the sample by an ion implanting method. Before a heat treatment for activating the introduced antimony is conducted, the film 43 is removed to a part including the region in which the antimony is introduced at least from the surface. This sample is heat treated as prescribed to obtain an N-type impurity diffused layer 47.