There is provided an Al bonding wire which can provide a sufficient bonding reliability of bonded parts of the bonding wire under a high temperature state where a semiconductor device using the Al bonding wire is operated. The bonding wire is composed of Al or Al alloy, and is characterized in that an average crystal grain size in a cross-section of a core wire in a direction perpendicular to a wire axis of the bonding wire is 0.01 to 50 ?m, and when measuring crystal orientations on the cross-section of the core wire in the direction perpendicular to the wire axis of the bonding wire, a crystal orientation <111> angled at 15 degrees or less to a wire longitudinal direction has a proportion of 30 to 90% among crystal orientations in the wire longitudinal direction.

A copper-based alloy wire made of a material selected from the group consisting of a copper-gold alloy, a copper-palladium alloy and a copper-gold-palladium alloy is provided. The alloy wire has a polycrystalline structure of a face-centered cubic lattice and consists of a plurality of equi-axial grains. The quantity of grains having annealing twins is 10 percent or more of the total quantity of the grains of the copper-based alloy wire.

A bonding wire for a semiconductor device includes a Cu alloy core material and a Pd coating layer formed on a surface thereof. Containing an element that provides bonding reliability in a high-temperature environment improves the bonding reliability of the ball bonded part in high temperature. Furthermore, making an orientation proportion of a crystal orientation <100> angled at 15 degrees or less to a wire longitudinal direction among crystal orientations in the wire longitudinal direction 30% or more when measuring crystal orientations on a cross-section of the core material in a direction perpendicular to a wire axis of the bonding wire, and making an average crystal grain size in the cross-section of the core material in the direction perpendicular to the wire axis of the bonding wire 0.9 to 1.5 m provides a strength ratio of 1.6 or less.

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)

A bonding wire for a semiconductor device includes a Cu alloy core material and a Pd coating layer on a surface of the Cu alloy core material, and contains Ga and Ge of 0.011 to 1.2% by mass in total, which is able to increase bonding longevity of the ball bonded part in the high-temperature, high-humidity environment, and thus to improve the bonding reliability. The thickness of the Pd coating layer is preferably 0.015 to 0.150 m. When the bonding wire further contains one or more elements of Ni, Ir, and Pt in an amount, for each element, of 0.011 to 1.2% by mass, it is able to improve the reliability of the ball bonded part in a high-temperature environment at 175 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.

A bonding wire for a semiconductor device includes a Cu alloy core material and a Pd coating layer on a surface of the Cu alloy core material, and contains Ga and Ge of 0.011 to 1.2% by mass in total, which is able to increase bonding longevity of the ball bonded part in the high-temperature, high-humidity environment, and thus to improve the bonding reliability. The thickness of the Pd coating layer is preferably 0.015 to 0.150 m. When the bonding wire further contains one or more elements of Ni, Ir, and Pt in an amount, for each element, of 0.011 to 1.2% by mass, it is able to improve the reliability of the ball bonded part in a high-temperature environment at 175 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.

A bonding wire for a semiconductor device includes a Cu alloy core material and a Pd coating layer on a surface of the Cu alloy core material, and contains Ga and Ge of 0.011 to 1.2% by mass in total, which is able to increase bonding longevity of the ball bonded part in the high-temperature, high-humidity environment, and thus to improve the bonding reliability. The thickness of the Pd coating layer is preferably 0.015 to 0.150 m. When the bonding wire further contains one or more elements of Ni, Ir, and Pt in an amount, for each element, of 0.011 to 1.2% by mass, it is able to improve the reliability of the ball bonded part in a high-temperature environment at 175 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.

A bonding wire for a semiconductor device includes a Cu alloy core material and a Pd coating layer on a surface of the Cu alloy core material, and contains Ga and Ge of 0.011 to 1.2% by mass in total, which is able to increase bonding longevity of the ball bonded part in the high-temperature, high-humidity environment, and thus to improve the bonding reliability. The thickness of the Pd coating layer is preferably 0.015 to 0.150 m. When the bonding wire further contains one or more elements of Ni, Ir, and Pt in an amount, for each element, of 0.011 to 1.2% by mass, it is able to improve the reliability of the ball bonded part in a high-temperature environment at 175 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.

A bonding wire for a semiconductor device including a coating layer having Pd as a main component on the surface of a Cu alloy core material and a skin alloy layer containing Au and Pd on the surface of the coating layer has a Cu concentration of 1 to 10 at % at an outermost surface thereof and has the core material containing a metallic element of Group 10 of the Periodic Table of Elements in a total amount of 0.1 to 3.0% by mass, thereby achieving improvement in 2nd bondability and excellent ball bondability in a high-humidity heating condition. Furthermore, a maximum concentration of Au in the skin alloy layer is preferably 15 at % to 75 at %.

A bonding wire for a semiconductor device includes a Cu alloy core material and a Pd coating layer formed on a surface thereof. Containing an element that provides bonding reliability in a high-temperature environment improves the bonding reliability of the ball bonded part in high temperature. Furthermore, making an orientation proportion of a crystal orientation <100> angled at 15 degrees or less to a wire longitudinal direction among crystal orientations in the wire longitudinal direction 30% or more when measuring crystal orientations on a cross-section of the core material in a direction perpendicular to a wire axis of the bonding wire, and making an average crystal grain size in the cross-section of the core material in the direction perpendicular to the wire axis of the bonding wire 0.9 to 1.5 m provides a strength ratio of 1.6 or less.