Patent ID: 7638421

Claim:
A manufacturing method for a semiconductor device including a protrusion electrode for flip chip connection, the method comprising the steps of: forming a passivation film that covers a surface of a semiconductor substrate on which electrodes made of metal have been formed, in which an opening is formed so as to expose a predetermined electrode from among the electrodes; forming a diffusion prevention plug made of a first metal in the vicinity of the opening in the passivation film; supplying a second metal material to the surface of the semiconductor substrate on which the diffusion prevention plug has been formed, so as to form a seed layer made of the second metal; forming a resist film that covers the seed layer and in which an opening is formed so as to expose a predetermined region of the seed layer on the diffusion prevention plug; supplying a third metal material into the opening in the resist film so as to form the protrusion electrode made of the third metal; removing the resist film after the step of forming the protrusion electrode; and removing the seed layer after the step of forming the protrusion electrode, wherein the first metal of the diffusion prevention plug prevents an occurrence of diffusion between the metal of the electrodes and the third metal, wherein, in the step of forming the diffusion prevention plug, a forming region of the diffusion prevention plug is set so that the seed layer is in contact with the passivation film in the step of forming the seed layer, and wherein, in the step of forming the diffusion prevention plug, the diffusion prevention plug is formed so that a height of the diffusion prevention plug is higher throughout a portion corresponding to the opening in the passivation film than an upper surface of a region of the seed layer that is formed in the step of forming the seed layer, the region of the seed layer being in contact with the passivation film.