A method of forming an electrical contact is provided. The method may include depositing, by atomic layer deposition, a passivation layer over at least a region of a metal surface, wherein the passivation layer may include aluminum oxide, and electrically contacting the region of the metal surface with a metal contact structure, wherein the metal contact structure may include copper.

A bonding wire for a semiconductor device includes a Cu alloy core material and a Pd coating layer formed on a surface thereof, and the boding wire contains one or more elements of As, Te, Sn, Sb, Bi and Se in a total amount of 0.1 to 100 ppm by mass. The bonding longevity of a ball bonded part can increase in a high-temperature and high-humidity environment, improving the bonding reliability. When the Cu alloy core material further contains one or more of Ni, Zn, Rh, In, Ir, Pt, Ga and Ge in an amount, for each, of 0.011 to 1.2% by mass, it is able to increase the reliability of a ball bonded part in a high-temperature environment of 170 C. or more. When an alloy skin layer containing Au and Pd is further formed on a surface of the Pd coating layer, wedge bondability improves.