[16p-A409-1~17] 6.1 Ferroelectric thin films

△ [16p-A409-15] SMR based on epitaxial acoustic Bragg reflector and epitaxial piezoelectric thin films

〇Satoshi Tokai^1,2, Takahiko Yanagitani^1,2,3,4,5 (1.Waseda Univ., 2.ZAIKEN, 3.JST-CREST, 4.JST-FOREST, 5.JST-START)

Keywords:SMR, epitaxial growth, BAW filter

In BAW filters, excellent steepness (Q-value) is desired to prevent interference between dense radio bands. The use of single-crystal thin films in the piezoelectric layers is expected to improve the Q-value. In this study, acoustic Bragg reflectors were epitaxially grown on a sapphire single-crystal substrate by using metallic thin films for both high/low acoustic impedance layers of the SMR. The piezoelectric thin film was epitaxially grown on top of it, and an attempt was made to realize an SMR in which all layers consisted of epitaxial thin films.