[19p-P6-1~17] 6.4 Thin films and New materials

[19p-P6-5] Influence of Elements Addition on Crystal Structure of AlN Piezoelectric Thin Film

Saki Tanaka², 〇Masato Uehara^1,2, Sri Ayu Anggraini¹, Tetsuya Okuyama³, Hiroshi Yamada^1,2, Morito Akiyama¹ (1.AIST, 2.Kyushu Univ., 3.Kurume NCT)

Keywords:aluminium nitride, piezoelectric thin film, crystal structure

c-axis oriented AlN thin film is a piezoelectric material, and is used as a sensor or a RF filter. We have found that the piezoelectric coefficient dramatically increases with the addition of Sc or Mg-Nb. In addition, several element pairs that increase the piezoelectric coefficient have been reported. These papers point out that these additives reduce the lattice constant ratio c/a. In this study, we investigated the influence on the crystal structure by adding several elements, and found that the crystal structure changes depending on the element.