Cu alloy core bonding wire with Pd coating for semiconductor device

Patent metadata

Field	Value
Publication number	US-10497663-B2
Application number	US-201916248531-A
Country	US
Kind code	B2
Filing date	Jan 15, 2019
Priority date	May 26, 2015
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

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.

First claim

The invention claimed is:

1. A bonding wire for a semiconductor device comprising:
a Cu alloy core material; and
a Pd coating layer formed on a surface of the Cu alloy core material, wherein
the bonding wire contains at least one or more first elements selected from Sb, Bi and Se,
a concentration of the first 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; and Bi≤1 ppm by mass, and
the bonding wire contains at least one or more second elements selected from Ni, Zn, Rh, In, Ir, Pt, Ga and Ge, and
a concentration of each of the second elements is 0.011% by mass or more and 1.2% by mass or less relative to the entire wire.

2. The bonding wire for a semiconductor device according to claim 1 , wherein the concentration of the at least one or more first elements selected from Sb, Bi and Se in total is 1 ppm by mass or more and 100 ppm by mass or less relative to the entire wire.

3. 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.

4. 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.

5. The bonding wire for a semiconductor device according to claim 4 , wherein a thickness of the alloy skin layer containing Au and Pd is 0.0005 μm or more and 0.050 μm or less.

6. The bonding wire for a semiconductor device according to claim 1 , wherein
the Cu alloy core material contains Pd, and
a concentration of Pd contained in the Cu alloy core material is 0.05% by mass or more and 1.2% by mass or less.

7. The bonding wire for a semiconductor device according to claim 1 , wherein
the bonding wire further contains at least one or more third elements selected from B, P, Mg, Ca and La, and
a concentration of each of the third elements is 1 ppm by mass or more and 100 ppm by mass or less relative to the entire wire.

8. The bonding wire for a semiconductor device according to claim 1 , wherein, in a measurement result when measuring crystal orientations on a surface of the bonding wire, a crystal orientation <111> angled at 15 degrees or less to a longitudinal direction of the bonding wire has a proportion of 30% or more and 100% or less.

9. The bonding wire for a semiconductor device according to claim 1 , wherein Cu is present at an outermost surface of the bonding wire.

10. The bonding wire for a semiconductor device according to claim 1 , wherein a concentration of Sb is 9.9 ppm by mass or less relative to the entire wire.

11. A bonding wire for a semiconductor device comprising:
a Cu alloy core material; and
a Pd coating layer formed on a surface of the Cu alloy core material, wherein
the bonding wire contains at least one or more first elements selected from Sb, Bi and Se, and
when containing Sb, a concentration of Sb is 2.2 ppm by mass or more and 10 ppm by mass or less relative to the entire wire,
when containing Bi, a concentration of Bi is 0.2 ppm by mass or more and 1 ppm by mass or less relative to the entire wire, and
when containing Se, a concentration of Se is 1.2 ppm by mass or more and 4.9 ppm by mass or less relative to the entire wire.

12. The bonding wire for a semiconductor device according to claim 11 , wherein
the bonding wire further contains at least one or more second elements selected from Ni, Zn, Rh, In, Ir, Pt, Ga and Ge, and
a concentration of each of the second elements is 0.011% by mass or more and 1.2% by mass or less relative to the entire wire.

13. The bonding wire for a semiconductor device according to claim 11 , wherein the concentration of the at least one or more first elements selected from Sb, Bi and Se in total is 1 ppm by mass or more relative to the entire wire.

14. The bonding wire for a semiconductor device according to claim 11 , wherein a thickness of the Pd coating layer is 0.015 μm or more and 0.150 μm or less.

15. The bonding wire for a semiconductor device according to claim 11 , further comprising an alloy skin layer containing Au and Pd on the Pd coating layer.

16. The bonding wire for a semiconductor device according to claim 15 , wherein a thickness of the alloy skin layer containing Au and Pd is 0.0005 μm or more and 0.050 μm or less.

17. The bonding wire for a semiconductor device according to claim 11 , wherein
the Cu alloy core material contains Pd, and
a concentration of Pd contained in the Cu alloy core material is 0.05% by mass or more and 1.2% by mass or less.

18. The bonding wire for a semiconductor device according to claim 11 , wherein
the bonding wire further contains at least one or more third elements selected from B, P, Mg, Ca and La, and
a concentration of each of the third elements is 1 ppm by mass or more and 100 ppm by mass or less relative to the entire wire.

19. The bonding wire for a semiconductor device according to claim 11 , wherein, in a measurement result when measuring crystal orientations on a surface of the bonding wire, a crystal orientation <111> angled at 15 degrees or less to a longitudinal direction of the bonding wire has a proportion of 30% or more and 100% or less.

20. The bonding wire for a semiconductor device according to claim 11 , wherein Cu is present at an outermost surface of the bonding wire.

21. The bonding wire for a semiconductor device according to claim 11 , wherein a concentration of Sb is 9.9 ppm by mass or less relative to the entire wire.

Assignees

• Nippon Micrometal Corp
• Nippon Steel Chemical & Mat Co Ltd

Inventors

• Yamada Takashi
• Oda Daizo
• Haibara Teruo
• Uno Tomohiro

Classifications

• H10W72/522

  Multilayered bond wires, e.g. having a coating concentric around a core · CPC title

• H10W72/553

  not comprising solid metals or solid metalloids, e.g. polymers, ceramics or liquids · CPC title

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W72/07555

  changes in materials · CPC title

• H10W72/07552

  changes in structures or sizes · CPC title