2014 Fiscal Year Final Research Report
Fast phase change speed induced by surface oxidation of phase change material
Project/Area Number |
25630289
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Research Category |
Grant-in-Aid for Challenging Exploratory Research
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Allocation Type | Multi-year Fund |
Research Field |
Composite materials/Surface and interface engineering
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Research Institution | Tohoku University |
Principal Investigator |
SUTOU Yuji 東北大学, 工学(系)研究科(研究院), 准教授 (80375196)
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Co-Investigator(Renkei-kenkyūsha) |
KOIKE Junichi 東北大学, 未来科学技術共同研究センター, 教授 (10261588)
ANDO Daisuke 東北大学, 大学院工学研究科, 助教 (50615820)
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Project Period (FY) |
2013-04-01 – 2015-03-31
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Keywords | 相変化メモリ / 不揮発性メモリ / 表面酸化 / 不均一核生成 / 結晶化 |
Outline of Final Research Achievements |
Phase change random access memory (PCRAM) has attracted much attention as a new class of non-volatile memory because of its low production cost and high scalability. Now, Ge-Sb-Te material is used for PCRAM because of its fast phase change speed and good repeatability. However, the Ge-Sb-Te shows low crystallization temperature (Tc) and consequently insufficient high temperature data retention. Meanwhile, a material with a high Tc shows a slow phase change speed. Therefore, an idea to realize a material with high Tc and fast crystallization speed is desired. In this study, we investigated the effect of preferential surface oxidation on crystallization speed in GeTe-Si phase change material. It was found that the crystallization starting time of the surface-oxidized film by O2 plasma-treatment was about 20% faster than that of a non-oxidized film. This fast crystal nucleation was suggested to be due to the formation of inhomogeneous nucleation sites at the film surface.
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Free Research Field |
材料工学
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