Bonding wire for semiconductor
View Patent ↗A bonding wire for semiconductor includes: a core wire of copper or a copper alloy; a coating layer containing palladium and having a thickness of 10 to 200 nm; and an alloy layer formed on a surface of the coating layer. The alloy layer contains a noble metal and palladium and having a thickness of 1 to 80 nm. The noble metal is either gold or silver, and a concentration of the noble metal in the alloy layer is not less than 10% and not more than 75% by volume.
1. A bonding wire for semiconductor, comprising:
a core wire made of copper or a copper alloy;
a coating layer containing palladium, said coating layer being formed on a surface of said core wire, and having a thickness of 10 to 200 nm; and
an alloy layer containing noble metal and palladium, said alloy layer being formed on a surface of said coating layer, and having a thickness of 1 to 80 nm,
wherein said noble metal is gold, and a concentration of the gold in said alloy layer is not less than 10% and not more than 75% by volume, and
wherein of surface crystal grains in said alloy layer, the surface crystal grains having <111> crystal orientations angled at 15 degrees or less to a wire drawing direction occupy an areal percentage of 40% to 100%.
2. The bonding wire for semiconductor according to claim 1 , wherein the gold concentration in said alloy layer is not less than 15% and not more than 75% by volume.
3. The bonding wire for semiconductor according to claim 2 , wherein the gold concentration in said alloy layer is not less than 40% and not more than 75% by volume.
4. A bonding wire for semiconductor, comprising:
a core wire made of copper or a copper alloy;
a coating layer containing palladium, said coating layer being formed on a surface of said core wire, and having a thickness of 10 to 200 nm; and
an alloy layer containing noble metal and palladium, said alloy layer being formed on a surface of said coating layer, and having a thickness of 1 to 80 nm,
wherein said noble metal is silver, and a concentration of the silver in said alloy layer is not less than 10% and not more than 75% by volume, and
wherein of surface crystal grains in said alloy layer, the surface crystal grains having <100> crystal orientations angled at 15 degrees or less to a wire drawing direction occupy an areal percentage of 50% to 100%.
5. A bonding wire for semiconductor, comprising:
a core wire made of copper or a copper alloy;
a coating layer containing palladium, said coating layer being formed on a surface of said core wire, and having a thickness of 10 to 200 nm; and
an alloy layer containing noble metal and palladium, said alloy layer being formed on a surface of said coating layer, and having a thickness of 1 to 80 nm,
wherein said noble metal is silver, and a concentration of the silver in said alloy layer is not less than 10% and not more than 75% by volume, and
wherein of surface crystal grains in said alloy layer, the surface crystal grains having <111> crystal orientations angled at 15 degrees or less to a wire drawing direction occupy an areal percentage of 60% to 100%.
6. The bonding wire for semiconductor according to claim 1 , wherein a Meyer hardness of a surface of said bonding wire is 0.2 GPa to 2.0 GPa.
7. The bonding wire for semiconductor according to claim 1 , wherein said core wire contains at least one of B, P and Se in a total amount of 5 to 300 ppm by mass.
8. The bonding wire for semiconductor according to claim 4 , wherein said alloy layer has a thickness from 1 nm to 30 nm, and the sliver concentration in said alloy layer is not less than 10% and not more than 70% by volume.
9. The bonding wire for semiconductor according to claim 4 , wherein the sliver concentration in said alloy layer is not less than 20% and not more than 70% by volume.
10. The bonding wire for semiconductor according to claim 4 , wherein a Meyer hardness of a surface of said bonding wire is 0.2 GPa to 2.0 GPa.
11. The bonding wire for semiconductor according to claim 4 , wherein said core wire contains at least one of B, P and Se in a total amount of 5 to 300 ppm by mass.
12. The bonding wire for semiconductor according to claim 5 , wherein said alloy layer has a thickness from 1 nm to 30 nm, and the sliver concentration in said alloy layer is not less than 10% and not more than 70% by volume.
13. The bonding wire for semiconductor according to claim 5 , wherein the sliver concentration in said alloy layer is not less than 20% and not more than 70% by volume.
14. The bonding wire for semiconductor according to claim 5 , wherein a Meyer hardness of a surface of said bonding wire is 0.2 GPa to 2.0 GPa.
15. The bonding wire for semiconductor according to claim 5 , wherein said core wire contains at least one of B, P and Se in a total amount of 5 to 300 ppm by mass.