1993 Fiscal Year Final Research Report Summary
Observation and control of the interfacial reaction of multilayr thin films for lead bonding wire using optical reflectivity technique.
Project/Area Number |
04452281
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Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
金属材料(含表面処理・腐食防食)
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Research Institution | Osaka University |
Principal Investigator |
UMAKOSHI Yukichi Osaka University, Department of Materials Science and Engineering, Faculty of Engineering, Professor, 工学部, 教授 (00029216)
|
Co-Investigator(Kenkyū-buntansha) |
SHIBAYANAGI Toshiya Osaka University, Department of Materials Science and Engineering, Faculty of En, 工学部, 助手 (10187411)
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Project Period (FY) |
1992 – 1993
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Keywords | optical reflectivity / thin film / diffusion / semi-conductor / intermetallic compound / welding / lead bonding / diffusion of Au and Cu |
Research Abstract |
Formation of intermetallic phases in Al/Au and Al/Cu thinfilm couples annealed at temperatures between 100゚C and 250゚C has been investigated using X-ray diffraction and optical reflectivity technique. The Au or Cu metals with the thickness of 100nm were first deposited on SiO_2 plate and then Al thin film with the thickness of 100nm was produced on the Au or Cu film in vacuum. Formation of several intermetallic compounds was confirmed by X-ray analysis after annealing. The formation and growth of Al_2Cu, AlCu and Al_2Au could be observed by the variation of optical reflectivity with wavelength. The inter-diffusion of metals in Al/Au thin film occurred faster than that in Al/Cu during annealing. For example, the growth rate constants (k) of Al_2Au and Al_2Cu layrs in thin film couples annealed at 200゚C were 3.4x10^<-6> and 2.4x10^<-7> cm/sec^<1/2>, respectively. The growth rate of these intermetallic layrs was faster in thin films than in diffusion couples of bulk metals. The strength of interfacial reaction products between Al and Cu was investigated using indentation test. The strength increased rapidly with increasign time and thickness of reaction zone, and then decreased. An appropriate thickness of the reaction zone at the interface contributed to the improvement of the strength of Al-Cu lead bonding wires.
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Research Products
(2 results)