Construction on anomalous heat transport theory for metal/oxide/metal three-layer thin film

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H02087
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 19020:Thermal engineering-related
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Yamashita Yuichiro 国立研究開発法人産業技術総合研究所, 計量標準総合センター, 主任研究員 (60462834)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: ナノスケール熱輸送 / サーモリフレクタンス測定 / 伝熱シミュレーション / スパッタリング / 酸化物薄膜 / 熱伝導率

Outline of Final Research Achievements

Metal/metal oxide/metal 3-layer films exhibit anomalous heat transport, i.e. a drastic reduction in the thermal resistance for the interfaces and the interlayer, when the interlayer thickness is approximately less than 3 nm. The purpose of this research is to elucidate the mechanism of this anomalous heat transport based on experimental and computational approaches. From the experiment, the anomalous heat transport starts below about 3 nm HfO2 thickness, in agreement with previous reports. Furthermore, the numerical simulation shows that the interface roughness between Mo and HfO2 causes the effective reduction of the thermal resistance. It is therefore concluded that this anomalous heat transport is due to nanoscale interface roughness.

Free Research Field

ナノスケール熱計測

Academic Significance and Societal Importance of the Research Achievements

表面粗さに伴う伝熱促進は主に固体―液体、固体―気体の界面を対象に研究されてきた。本研究成果はナノスケールの界面ラフネスを持つ極薄金属酸化物薄膜について、その両側を高熱伝導性の金属膜で挟めば、固体―固体界面においても顕著な熱抵抗減少（伝熱促進）効果が現れる事を実験と計算の両面で示した。これより固体デバイスの高効率エネルギー利用につながるナノスケールでの伝熱性能向上に向けた界面エンジニアリングへの発展が期待される。