Semiconductor device and manufacturing method thereof with Cu and Sn intermetallic compound
A method of manufacturing a semiconductor device which includes a plurality of members including a semiconductor element is provided. The method may include disposing one surface of a first member which is one of the plurality of members and one surface of a second member which is another one of the plurality of members opposite to each other with a tin-based (Sn-based) solder material interposed therebetween, and bonding the first member and the second member by melting and solidifying the Sn-based solder material. At least the one surface of the first member may be constituted of a nickel-based (Ni-based) metal, and at least the one surface of the second member may be constituted of copper (Cu).
1. A method of manufacturing a semiconductor device which comprises a plurality of members including a semiconductor element, the method comprising:
disposing one surface of a first member which is one of the plurality of members and one surface of a second member which is another one of the plurality of members opposite to each other with a tin-based (Sn-based) solder material interposed therebetween; and
bonding the first member and the second member by melting and solidifying the Sn-based solder material,
wherein
at least the one surface of the first member is constituted of a nickel-based (Ni-based) metal,
at least the one surface of the second member is constituted of copper (Cu),
in bonding the first member and the second member, Cu 3 Sn and (Cu,Ni) 6 Sn 5 are generated in this order on the one surface of the second member while the Sn-based solder material solidifies, and
the generated (Cu,Ni) 6 Sn 5 contains Ni atoms derived from the Ni-based metal dissolved into the Sn-based solder material from the first member.
2. The method according to claim 1 , wherein
in bonding the first member and the second member, (Cu,Ni) 6 Sn 5 is generated on the one surface of the first member while the Sn-based solder material solidifies.
3. The method according to claim 1 , wherein
bonding the first member and the second member includes holding a temperature of the Sn-based solder material for a predetermined time period within a temperature range higher than a melting temperature of the Sn-based solder material.
4. The method according to claim 3 , wherein
in holding the temperature of the Sn-based solder material, a concentration of Cu in the Sn-based solder material is increased by dissolving copper from the one surface of the second member into melted Sn-based solder material.
5. The method according to claim 4 , wherein
holding the temperature of the Sn-based solder material is performed under a condition that the concentration of Cu in the Sn-based solder material reaches 0.7 mass % or more.
6. The method according to claim 4 , wherein
holding the temperature of the Sn-based solder material is performed under a condition that the concentration of Cu in the Sn-based solder material reaches 3.0 mass % or more.
7. The method according to claim 1 , wherein
the first member is the semiconductor element including an electrode, and
the one surface of the first member is a surface of the electrode of the semiconductor element.
8. The method according to claim 1 , wherein
the one surface of the first member is covered with a gold or silver film before bonding the first member and the second member, and
the gold or silver film diffuses into the Sn-based solder material while the Sn-based solder material is melted during bonding the first member and second member.