Method of manufacturing semiconductor device

A method of manufacturing a semiconductor device, comprising the steps of:

• (a) providing a semiconductor wafer having a first surface, a pad electrode formed on the first surface, a first insulating film formed on the first surface and having a first opening through which a part of the pad electrode is exposed, a first conductive layer formed on a surface of the first insulating film and electrically connected with the pad electrode through an inner side of the first opening, a second insulating film formed on a surface of the first conductive layer and having a second opening through which a part of the first conductive layer is exposed, and a second conductive layer formed on the surface of the first conductive layer in the second opening;
• (b) after the step (a), removing the second insulating film,
• (c) after the step (b), removing a part of the first conductive layer not overlapping with the second conductive layer;
• (d) after the step (c), mounting a semiconductor chip obtained by cutting the semiconductor wafer on a base material via a die bonding material;
• (e) after the step (d), irradiating the semiconductor chip with argon ions;
• and
• (f) after the step (e), bringing a part of a bonding wire into contact with a surface of the second conductive layer of the semiconductor chip,
• wherein, before the step (c), a protective film comprised of iodine is formed on the surface of the second conductive layer, and
• wherein the protective film is removed at the step (e).