A method of forming a microelectronic device structure comprises coiling a portion of a wire up and around at least one sidewall of a structure protruding from a substrate. At least one interface between an upper region of the structure and an upper region of the coiled portion of the wire is welded to form a fused region between the structure and the wire.

There is provided an Al bonding wire which can achieve a sufficient bonding reliability of bonded parts of the bonding wire under a high temperature state where a semiconductor device using the Al bonding wire is operated. The Al bonding wire is characterized in that the wire contains 0.02 to 1% by mass of Fe, further contains 0.05 to 0.5% by mass in total of at least one or more of Mn and Cr, and the balance includes Al and inevitable impurities, wherein a total content of Fe, Mn and Cr in solid solution is 0.01 to 1% by mass. The Al bonding wire contains Mn and Cr in addition to Fe, so that Fe, Mn and Cr can be promoted to form a solid solution in quenching treatment after the solution treatment. Accordingly, the Al bonding wire can achieve an effect of solid-solution strengthening of the wire due to the increase in the total content of Fe, Mn and Cr in solid solution and an effect of preventing recrystallization from proceeding during use of the semiconductor device at a high temperature for a long time.