PIEZOELECTRIC DEVICE

• Main Authors: ITO KOREKIYO, IWAMOTO TAKASHI
• Format: Patent
• Language: English; Japanese
• Published: 29.10.2015
• Subjects: BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS

PROBLEM TO BE SOLVED: To provide a piezoelectric device which enables the enhancement of electric power proofness of an electrode formed on a piezoelectric thin film, and enables the large decrease in the concentration of etchant and an etching time.SOLUTION: A piezoelectric device is produced by the steps of: etching, of a +C plane 22 of a piezoelectric thin film 20 on +Z-axis side and its -C plane 12 on -Z-axis side, the -C plane 12 on -Z-axis side of the piezoelectric thin film 20, thereby exposing -Z plane 21 of the piezoelectric thin film 20 which enables an epitaxial growth; subsequently, epitaxially growing Ti on the -Z plane 21 of the piezoelectric thin film 20 in -Z-axis direction so that its crystal growth plane (001) is in parallel with the -Z plane 21 of the piezoelectric thin film 20; and then, epitaxially growing Al on the surface of the resultant Ti electrode 65 in -Z-axis direction so that its crystal growth plane (111) is in parallel with the -Z plane 21 of the piezoelectric thin film 20. 【課題】圧電薄膜上に形成する電極の耐電力性を向上させるとともに、エッチング液の濃度やエッチング時間を大幅に低減させることができる圧電デバイスを提供する。【解決手段】圧電薄膜２０の＋Ｚ軸側の＋Ｃ面２２と圧電薄膜２０の−Ｚ軸側の−Ｃ面１２とのうち、圧電薄膜２０の−Ｚ軸側の−Ｃ面１２をエッチングする。これにより、エピタキシャル成長可能な圧電薄膜２０の−Ｚ面２１を露出させる。そして、Ｔｉを、結晶成長面（００１）が圧電薄膜２０の−Ｚ面２１と平行になるよう圧電薄膜２０の−Ｚ面２１に−Ｚ軸方向へエピタキシャル成長させる。次に、Ａｌを、結晶成長面（１１１）が圧電薄膜２０の−Ｚ面２１と平行になるようＴｉ電極６５の表面に−Ｚ軸方向へエピタキシャル成長させる。【選択図】 図６