Bonding wire for semiconductor device
View Patent ↗It is an object of the present invention to provide a copper-based bonding wire whose material cost is low, having excellent ball bondability, reliability in a heat cycle test or reflow test, and storage life, enabling an application to thinning of a wire used for fine pitch connection. The bonding wire includes a core material having copper as a main component and an outer layer which is provided on the core material and contains a metal M and copper, in which the metal M differs from the core material in one or both of components and composition. The outer layer is 0.021 to 0.12 μm in thickness.
1. A semiconductor device bonding wire comprising:
a core material whose components include copper as a main component, and
an outer layer provided on said core material, said outer layer containing a metal M that differs from said core material in one or both of components and composition, and copper, said outer layer being 0.021 to 0.12 μm in thickness,
wherein said metal M is Pd,
said outer layer is a region where a concentration of Pd is 50 mol % or more, and
a region where a concentration of said metal M relative to a total of the metallic elements is 10 mol % or more is 0.03 to 0.2 μm in thickness.
2. The semiconductor device bonding wire according to claim 1 , wherein said core material including copper as a main component contains at least one element selected from among P, B, Ir, Zr, Bi, Ti, Au, Ag, Sn and rare-earth elements, and an elemental concentration of said at least one element relative to the whole of the wire is in a range of from 0.0001 to 0.03 mol % in total.
3. A semiconductor device bonding wire, comprising:
a core material whose components include copper as a main component, and an outer layer provided on said core material, said outer layer containing a metal M that differs from said core material in one or both of components and composition, and copper, said outer layer being 0.021 to 0.12 gm in thickness,
wherein said metal M is Pd,
said outer layer is a region where a concentration of Pd is 50 mol % or more and contains at least one element selected from among Bi, P, Se and Tl, and
an elemental concentration of said at least one element on a surface of said outer layer is in a range of from 0.01 to 5 mol % in total.
4. The semiconductor device bonding wire according to claim 1 , wherein a diffusion layer is provided between said outer layer and said core material.
5. A semiconductor device bonding wire comprising:
a core material whose components include copper as a main component, and
an outer layer provided on said core material, said outer layer containing a metal M that differs from said core material in one or both of components and composition, and copper, said outer layer being 0.021 to 0.12 μm in thickness,
wherein said metal M is Pd,
said outer layer is a region where a concentration of Pd is 50 mol % or more, and
a region inside said outer layer where a total concentration of said metal M relative to a total of the metallic elements is 90 mol % or more is 0.004 to 0.07 μm in thickness.
6. The semiconductor device bonding wire according to claim 1 , wherein a region inside said outer layer where a total concentration of said metal M relative to a total of the metallic elements is 96 mol % or more is 0.002 to 0.06 μm in thickness.
7. The semiconductor device bonding wire according to claim 1 , wherein a copper concentration relative to a total of the metallic elements on a surface of the outer layer is 0.5 to 45 mol %.
8. The semiconductor device bonding wire according to claim 1 , wherein a region inside said outer layer where a copper concentration relative to a total of the metallic elements is in a range of from 1 to 30 mol % is 0.0005 to 0.008 μm in thickness.
9. The semiconductor device bonding wire according to claim 1 , wherein a concentration of said metal M, which is contained in an entire wire and is other than copper, relative to a total of the metallic elements is in a range of from 0.05 to 3 mol %.
10. The semiconductor device bonding wire according to claim 3 , wherein said core material including copper as a main component contains at least one element selected from among P, B, Ir, Zr, Bi, Ti, Au, Ag, Sn and rare-earth elements, and an elemental concentration of said at least one element relative to the whole of the wire is in a range of from 0.0001 to 0.03 mol % in total.
11. The semiconductor device bonding wire according to claim 3 , wherein a diffusion layer is provided between said outer layer and said core material.
12. The semiconductor device bonding wire according to claim 3 , wherein a region inside said outer layer where a total concentration of said metal M relative to a total of the metallic elements is 96 mol % or more is 0.002 to 0.06 μm in thickness.
13. The semiconductor device bonding wire according to claim 3 , wherein a copper concentration relative to a total of the metallic elements on a surface of the outer layer is 0.5 to 45 mol %.
14. The semiconductor device bonding wire according to claim 3 , wherein a region inside said outer layer where a copper concentration relative to a total of the metallic elements is in a range of from 1 to 30 mol % is 0.0005 to 0.008 μm in thickness.
15. The semiconductor device bonding wire according to claim 3 , wherein a concentration of said metal M, which is contained in an entire wire and is other than copper, relative to a total of the metallic elements is in a range of from 0.05 to 3 mol %.
16. The semiconductor device bonding wire according to claim 5 , wherein said core material including copper as a main component contains at least one element selected from among P, B, Ir, Zr, Bi, Ti, Au, Ag, Sn and rare-earth elements, and an elemental concentration of said at least one element relative to the whole of the wire is in a range of from 0.0001 to 0.03 mol % in total.
17. The semiconductor device bonding wire according to claim 5 , wherein a diffusion layer is provided between said outer layer and said core material.
18. The semiconductor device bonding wire according to claim 5 , wherein a region inside said outer layer where a total concentration of said metal M relative to a total of the metallic elements is 96 mol % or more is 0.002 to 0.06 μm in thickness.
19. The semiconductor device bonding wire according to claim 5 , wherein a copper concentration relative to a total of the metallic elements on a surface of the outer layer is 0.5 to 45 mol %.
20. The semiconductor device bonding wire according to claim 5 , wherein a region inside said outer layer where a copper concentration relative to a total of the metallic elements is in a range of from 1 to 30 mol % is 0.0005 to 0.008 μm in thickness.
21. The semiconductor device bonding wire according to claim 5 , wherein a concentration of said metal M, which is contained in an entire wire and is other than copper, relative to a total of the metallic elements is in a range of from 0.05 to 3 mol %.