Electrode of semiconductor device, method of manufacturing thereof, and the semicondutor device

A method of manufacturing an electrode of a semiconductor device comprising the steps of:

• forming a pad having an upper surface and side surfaces on a substrate surface;
• forming a passivation film on the substrate and on the side surfaces and portions of the upper surface of the pad, leaving an exposed portion of the upper surface of the pad;
• forming an electroless barrier metal film, as a pad protection film, on said exposed upper surface of the pad, the barrier metal film having side surfaces abutting the passivation film on the upper surface of the pad;
• and
• forming a solder precoat layer on a surface of said electroless barrier metal film, having a thickness so that an intermetallic compound layer having a bonded surface bonded substantially to the whole of the surface of said electroless barrier metal film is formed in said solder precoat layer in the vicinity of a boundary surface between said solder precoat film and said electroless barrier metal film.