Copper alloy bonding wire for semiconductor devices

Abstract

In a copper alloy bonding wire for semiconductor devices, the bonding longevity of a ball bonded part under high-temperature and high-humidity environments is improved. The copper alloy bonding wire for semiconductor devices includes in total 0.03% by mass or more to 3% by mass or less of at least one or more kinds of elements selected from Ni, Zn, Ga, Ge, Rh, In, Ir, and Pt (first element), with the balance Cu and inevitable impurities. The inclusion of a predetermined amount of the first element suppresses production of an intermetallic compound susceptible to corrosion under high-temperature and high-humidity environments at the wire bonding interface and improves the bonding longevity of a ball bonded part.

1 . A copper alloy bonding wire for semiconductor devices, comprising in total 0.03% by mass or more to 3% by mass or less of at least one or more kinds of elements selected from Ni, Zn, Ga, Ge, In, and Ir, with the balance comprising Cu and inevitable impurities, wherein the copper alloy bonding wire is bare Cu alloy wire. 
     
     
         2 . The copper alloy bonding wire for semiconductor devices according to  claim 1 , wherein an average crystal grain size (μm) in core cross section in a direction vertical to a wire axis of the copper alloy bonding wire is
   0.02×R+0.4 or more   (1a)
 
   0.1×R+0.5 or less   (1b)
 
 
       where R (μm) is a diameter of the wire. 
     
     
         3 . The copper alloy bonding wire for semiconductor devices according to  claim 1 , wherein an average film thickness of copper oxide on a surface of the wire is in a range of 0.0005 μm or more and 0.02 μm or less. 
     
     
         4 . The copper alloy bonding wire for semiconductor devices according to  claim 1 , wherein the copper alloy bonding wire further comprises 0.0001% by mass or more and 0.050% by mass or less of each of at least one or more kinds of elements selected from Ti, B, Ca, La, As, Te, and Se, with respect to the entire wire. 
     
     
         5 . The copper alloy bonding wire for semiconductor devices according to  claim 1 , wherein the copper alloy bonding wire further comprises in total 0.0005% by mass or more and 0.5% by mass or less of at least one or more kinds of elements selected from Ag and Au, with respect to the entire wire. 
     
     
         6 . The copper alloy bonding wire for semiconductor devices according to  claim 1 , wherein the copper alloy bonding wire further comprises 1.15% by mass or less of Pd. 
     
     
         7 . The copper alloy bonding wire for semiconductor devices according to  claim 1 , wherein the copper alloy bonding wire comprises two or more kinds of elements selected from Ni, Zn, Ga, Ge, In, and Ir. 
     
     
         8 . The copper alloy bonding wire for semiconductor devices according to  claim 4 , wherein the copper alloy bonding wire further comprises in total 0.0005% by mass or more and 0.5% by mass or less of at least one or more kinds of elements selected from Ag and Au, with respect to the entire wire. 
     
     
         9 . The copper alloy bonding wire for semiconductor devices according to  claim 4 , wherein the copper alloy bonding wire further comprises 1.15% by mass or less of Pd. 
     
     
         10 . The copper alloy bonding wire for semiconductor devices according to  claim 5 , wherein the copper alloy bonding wire further comprises 1.15% by mass or less of Pd. 
     
     
         11 . The copper alloy bonding wire for semiconductor devices according to  claim 8 , wherein the copper alloy bonding wire further comprises 1.15% by mass or less of Pd. 
     
     
         12 . The copper alloy bonding wire for semiconductor devices according to  claim 1 , wherein the copper alloy bonding wire does not have a coating layer based on a metal other than copper.