[19a-PB1-1~11] 9.1 Dielectrics, ferroelectrics

▲ [19a-PB1-4] Effect of MgTa addition on the piezoelectric response of aluminum nitride thin films

〇Sri Ayu Anggraini¹, Masato Uehara¹, Kenji Hirata¹, Hiroshi Yamada¹, Morito Akiyama¹ (1.AIST)

Keywords:piezoelectric, AlN, thin films

The ever-growing smartphone and wireless communication devices demand a continuous improvement in performance of bulk acoustic wave (BAW) filter which consequently also induce development of highly functional aluminum nitride (AlN) thin films as an integrated component in BAW filter. Other than having a highly c-oriented wurtzite structure, the functionality of AlN-based thin film can be tuned by alloying it with other elements while maintaining the optimum crystallinity. The most successful endeavor in enhancing the piezoelectric response of AlN was done by incorporating Sc, where doping 50 at.% Sc into AlN could raise the piezoelectric properties up to about 500% [1]. However, the use of relatively expensive such as Sc may raise the manufacturing cost, hence hindering a wider utilization of ScAlN. This has motivated numerous efforts in finding an inexpensive alternative dopant to substitute Sc. As an alternative dopant, Mg-based codopants are among the most investigated elements ever since it was proposed as the prospective dopants [2]. Addition of MgNb, MgTi, MgHf as codopants for AlN has been studied and confirmed to capable increasing the piezoelectric response of AlN [3-5]. Inspired by these findings, in this study, the effect of MgTa addition into AlN on the piezoelectric properties of the thin films is investigated.
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