PURPOSE: To provide a barrier metal in a good embedded state even at a contact hole having a high aspect ratio along with good barrier characteristics between a wiring layer and a lower semiconductor.

CONSTITUTION: A contact hole 3 is opened in an insulating layer 2 on a semiconductor substrate 1, and a wiring layer is embedded after a barrier metal made up of a refractory metallic layer 4 and/or a refractory metallic alloy compound layer 5a is formed at a contact hole 3. An impurity plasma beam with a directional characteristic is cast, as indicated by an arrow (p), on the refractory metallic layer 4 and/or the refractory metallic alloy compound layer 5a. Then, an impurity is implanted at least into an intergranular part of the refractory metallic layer 4 and/or the refractory metallic alloy compound layer 5a at a bottom part of the contact hole 3.