Formation Mechanism of Unique Voids in Cu Interconnects for ULSI
| Project/Area Number |
13650759
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural/Functional materials
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
MORIYAMA Miki Kyoto Univ., Research associate, 工学研究科, 助手 (70303857)
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| Co-Investigator(Kenkyū-buntansha) |
MURAKAMI Masanori Kyoto Univ., Professor, 工学研究科, 教授 (70229970)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2002: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2001: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | ULSI / Copper Interconnect / Reliability / Microvoid / Impurity / Si半導体デバイス / 水素脆性 |
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| Research Abstract |
Development to Cu interconnect is positively required in Si-ULSI(Ultra-Large-Scale Integrate) industries. The serious problem for the development is void formation, resulted in degradation of the performances and reliabilities in the Cu interconnects and Si devices. So far, mechanism of voiding in the Cu has been considered due to thermal stress and creep phenomena during annealing. The purpose in the present study is to investigate unique microvoid, which is completely different from the previous one, and to elucidate the mechanisms of the void formation in the Cu films.
Recently, the Cu interconnects are fabricated using electroplating and sputtering depositions. In both depsitin methods, impurities or precipitates such as organic additives and Cu oxide(Cu0) are commonly introduced in the Cu films during growth. These impurities in the Cu films may have strong influence on the void formation. In fact, the formation of voids in the Cu/Cu0/Cu multilayers deposited by sputtering was observed after annealing in H_2/N_2 atmosphere. It is clear that this voiding is resulted from the formation of H_20 bubbles produced by chemical reaction between 0 in Cu0 and H_2 in the atmosphere. In case of the electroplated Cu films, a lot of voids were formed at the interface between the film and the substrate after annealing. There is much possibility that the organic additives trigger off the voiding in the electroplating depositions. As a consequence, it is quite essential to understand and control the amount of these impurities for prevention of the void formation.
In the present study, we got precious knowledge of the voiding phenomena in the Cu films. The microvoids observed are unique from the point of view of the formation mechanism. Understandings of these unique voids will be strongly required fox the developments of high-performance and -reliable Cu interconnects.
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Report
(3 results)
Research Products
(6 results)
