Study on expansion of solubility limit of AlN-based piezoelectric thin films

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K14503
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 28030:Nanomaterials-related
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Hirata Kenji 国立研究開発法人産業技術総合研究所, エレクトロニクス・製造領域, 主任研究員 (40828282)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 窒化物 / 圧電体 / 固溶体 / 第一原理計算 / 薄膜

Outline of Final Research Achievements

In ScAlN thin films with high piezoelectric properties, theoretical calculations have revealed that YN with a rock-salt structure oriented to <111> is promising as a buffer layer for stabilizing the wurtzite phase with a high concentration of Sc. In MgWAlN, for which high piezoelectric properties were predicted by theoretical calculations, thin films composed of the wurtzite phase could be obtained. It was also found that the crystallinity and orientation of the wurtzite phase in ScAlN and MgWAlN thin films were greatly improved by introducing a thin AlN as a buffer layer.

Free Research Field

材料科学

Academic Significance and Societal Importance of the Research Achievements

本研究では、薄いAlNを下地層としてAlN系固溶体薄膜に導入することでウルツ鉱相の結晶性や配向性の大きな向上を確認することができた。この知見は、通信用機器の弾性波フィルタに用いられるAlN系圧電薄膜の性能向上に貢献するものと期待される。また、新規にMgWAlN薄膜において圧電応答を得ることができた。今後、圧電性能の向上を図ることができれば、本材料は圧電センサや弾性波フィルタへの応用が期待される。