Bonding wire for semiconductor devices
View Patent ↗A semiconductor-device bonding wire includes a core member formed of an electrically-conductive metal, and a skin layer mainly composed of a face-centered cubic metal different from the core member and formed thereon. An orientation ratio of <111> orientations in crystalline orientations <hkl> in a wire lengthwise direction at a crystal face of a surface of the skin layer is greater than or equal to 50%, and the <111> orientations have an angular difference relative to the wire lengthwise direction, the angular difference being within 15 degrees.
1. A bonding wire for semiconductor devices, the bonding wire comprising:
a core member formed of an electrically-conductive metal; and
a skin layer formed on the core member and mainly composed of a metal different from the core member, and wherein
the metal of the skin layer is a face-centered cubic metal,
a thickness of the skin layer is within a range from 0.005 to 0.09 μm,
an orientation ratio of <111> orientations in crystalline orientations <hkl> in a wire lengthwise direction at a crystal face of a surface of the skin layer is greater than or equal to 50%, and
said <111> orientations have an angular difference relative to the wire lengthwise direction, said angular difference being within 15 degrees.
2. The semiconductor-device bonding wire according to claim 1 , further comprising a diffusion layer formed between the skin layer and the core member and having a concentration gradient of each main constituent of the skin layer and the core member.
3. The semiconductor-device bonding wire according to claim 2 , wherein a main constituent of the skin layer is at least one of the followings: Pd; Pt; Ru; and Ag.
4. The semiconductor-device bonding wire according to claim 3 , wherein a main constituent of the core member is at least one of the followings: Cu; and Au.
5. The semiconductor-device bonding wire according to claim 4 , wherein the main constituent of the core member is Cu and the core member contains one or more of the followings: B; Pd; Bi; P; and Zr at a concentration within a range from 5 to 300 ppm in total.
6. The semiconductor-device bonding wire according to claim 4 , wherein the main constituent of the core member is Cu and the core member contains Pd at a concentration within a range from 5 to 10000 ppm, and the main constituent of the skin layer is Pd or Ag.
7. The semiconductor-device bonding wire according to claim 4 , wherein the main constituent of the core member is Au and the core member contains one or more of the followings: Be; Ca; Ni; Pd and Pt at a concentration within a range from 5 to 8000 ppm in total.
8. The semiconductor-device bonding wire according to claim 3 , wherein the main constituent of the core member is Cu and the core member contains one or more of the followings: B; Pd; Bi; P; and Zr at a concentration within a range from 5 to 300 ppm in total.
9. The semiconductor-device bonding wire according to claim 3 , wherein the main constituent of the core member is Cu and the core member contains Pd at a concentration within a range from 5 to 10000 ppm, and the main constituent of the skin layer is Pd or Ag.
10. The semiconductor-device bonding wire according to claim 3 , wherein the main constituent of the core member is Au and the core member contains one or more of the followings: Be; Ca; Ni; Pd and Pt at a concentration within a range from 5 to 8000 ppm in total.
11. The semiconductor-device bonding wire according to claim 2 , wherein a main constituent of the core member is at least one of the followings: Cu; and Au.
12. The semiconductor-device bonding wire according to claim 11 , wherein the main constituent of the core member is Cu and the core member contains one or more of the followings: B; Pd; Bi; P; and Zr at a concentration within a range from 5 to 300 ppm in total.
13. The semiconductor-device bonding wire according to claim 11 , wherein the main constituent of the core member is Cu and the core member contains Pd at a concentration within a range from 5 to 10000 ppm, and the main constituent of the skin layer is Pd or Ag.
14. The semiconductor-device bonding wire according to claim 11 , wherein the main constituent of the core member is Au and the core member contains one or more of the followings: Be; Ca; Ni; Pd and Pt at a concentration within a range from 5 to 8000 ppm in total.
15. The semiconductor-device bonding wire according to claim 1 , wherein a main constituent of the skin layer is at least one of the followings: Pd; Pt; Ru; and Ag.
16. The semiconductor-device bonding wire according to claim 15 , wherein a main constituent of the core member is at least one of the followings: Cu; and Au.
17. The semiconductor-device bonding wire according to claim 16 , wherein the main constituent of the core member is Cu and the core member contains one or more of the followings: B; Pd; Bi; P; and Zr at a concentration within a range from 5 to 300 ppm in total.
18. The semiconductor-device bonding wire according to claim 16 , wherein the main constituent of the core member is Cu and the core member contains Pd at a concentration within a range from 5 to 10000 ppm, and the main constituent of the skin layer is Pd or Ag.
19. The semiconductor-device bonding wire according to claim 16 , wherein the main constituent of the core member is Au and the core member contains one or more of the followings: Be; Ca; Ni; Pd and Pt at a concentration within a range from 5 to 8000 ppm in total.
20. The semiconductor-device bonding wire according to claim 15 , wherein the main constituent of the core member is Cu and the core member contains one or more of the followings: B; Pd; Bi; P; and Zr at a concentration within a range from 5 to 300 ppm in total.
21. The semiconductor-device bonding wire according to claim 15 , wherein the main constituent of the core member is Cu and the core member contains Pd at a concentration within a range from 5 to 10000 ppm, and the main constituent of the skin layer is Pd or Ag.
22. The semiconductor-device bonding wire according to claim 15 , wherein the main constituent of the core member is Au and the core member contains one or more of the followings: Be; Ca; Ni; Pd and Pt at a concentration within a range from 5 to 8000 ppm in total.
23. The semiconductor-device bonding wire according to claim 1 , wherein a main constituent of the core member is at least one of the followings: Cu; and Au.
24. The semiconductor-device bonding wire according to claim 23 , wherein the main constituent of the core member is Cu and the core member contains one or more of the followings: B; Pd; Bi; P; and Zr at a concentration within a range from 5 to 300 ppm in total.
25. The semiconductor-device bonding wire according to claim 23 , wherein the main constituent of the core member is Cu and the core member contains Pd at a concentration within a range from 5 to 10000 ppm, and the main constituent of the skin layer is Pd or Ag.
26. The semiconductor-device bonding wire according to claim 23 , wherein the main constituent of the core member is Au and the core member contains one or more of the followings: Be; Ca; Ni; Pd and Pt at a concentration within a range from 5 to 8000 ppm in total.