Method of cleaning a semiconductor substrate conductive layer surface

The residue organic material or a native oxide can sufficiently removed, and, without damaging the sidewall insulating film of the via hole to provide a cleaning method that is not a semiconductor substrate conductive layer surface which adversely affect the k value. Insulated film 2 is formed on a semiconductor substrate of the conductive layer 1 on the surface, it is carried to the semiconductor device via hole 4 for exposing a portion of the conductive layer 1 is formed in a reaction vessel in the insulating film 3, the reaction vessel by generating plasma containing hydrogen within the upper conductive layer 1 of the via hole 4 bottom cleaned, the residue organics 6 was decomposed and removed by ashing, to reduce the copper oxide film 7 of the conductive layer 1 on the surface of Cu.