Bonding wire for semiconductor device
A bonding wire for a semiconductor device, characterized in that the bonding wire includes a Cu alloy core material and a Pd coating layer formed on a surface of the Cu alloy core material, the bonding wire contains an element that provides bonding reliability in a high-temperature environment, and a strength ratio defined by the following Equation (1) is 1.1 to 1.6: Strength ratio=ultimate strength/0.2% offset yield strength. (1)
1. A bonding wire for a semiconductor device, the bonding wire comprising:
a Cu alloy core material; and
a Pd coating layer formed on a surface of the Cu alloy core material, wherein
a strength ratio defined by the following Equation (1) is 1.1 or more and 1.6 or less,
strength ratio=ultimate strength/0.2% offset yield strength Equation (1), and
the bonding wire meets at least one of the following conditions (i) and (ii):
(i) the bonding wire contains one or more elements selected from Co, Rh, Jr, Ni, Pd, Pt, Au, Zn, Al, Ga, In, and Ge; and
(ii) the bonding wire contains one or more elements selected from As, Sb, and Te, provided that:
a concentration of As is 2.5 ppm by mass or more;
a concentration of Sb is 5.2 ppm by mass or more; or
a concentration of Te is 1.2 ppm by mass or more.
2. The bonding wire for a semiconductor device according to claim 1 , wherein a thickness of the Pd coating layer is 0.015 μm or more and 0.150 μm or less.
3. The bonding wire for a semiconductor device according to claim 1 , further comprising an alloy skin layer containing Au and Pd on the Pd coating layer.
4. The bonding wire for a semiconductor device according to claim 3 , wherein a thickness of the alloy skin layer containing Au and Pd is 0.050 μm or less.
5. The bonding wire for a semiconductor device according to claim 1 , wherein
the bonding wire contains at least one element selected from Ni, Zn, Rh, In, Jr and Pt, and
a concentration of the at least one element in total is 0.011% by mass or more and 2% by mass or less relative to the entire wire.
6. The bonding wire for a semiconductor device according to claim 1 , wherein
the bonding wire contains one or more elements selected from Ga and Ge, and
a concentration of the elements in total is 0.011% by mass or more and 1.5% by mass
or less relative to the entire wire.
7. The bonding wire for a semiconductor device according to claim 1 , wherein
the bonding wire contains at least one or more elements selected from As, Te, and Sb,
a concentration of the elements in total is 0.1 ppm by mass or more and 100 ppm by mass or less relative to the entire wire, and
Sb≤10 ppm by mass.
8. The bonding wire for a semiconductor device according to claim 1 , wherein
the bonding wire further contains at least one element selected from B, P, Mg, Ca and La, and
a concentration of each of the at least one element is 1 ppm by mass or more and 200 ppm by mass or less relative to the entire wire.
9. The bonding wire for a semiconductor device according to claim 1 , wherein Cu is present at an outermost surface of the bonding wire.