On the other hand, the buffer film 8A1 which is the other constituent element of the connecting wiring 8 1 is formed specifically from a metal such as chromium (Cr), molybdenum (Mo), tungsten (W) or nickel (Ni), or a semiconductor, such as Si, Ge, GaAs or polysilicon, which contains an active impurity, or a silicide which is an alloy of a metal and silicon.