ACOUSTIC WAVE DEVICE WITH AN EFFICIENT STRUCTURE, A RADIO FREQUENCY MODULE, AND A MOBILE DEVICE INCLUDING THE SAME

Aspects and embodiments disclosed herein include an acoustic wave device comprising a substrate, a pair of inter-digital transducer (IDT) electrodes formed on the substrate, each of the pair of IDT electrodes including a bus bar and a plurality of fingers extending from the bus bar, fingers of one IDT electrode arranged interleaved with fingers of the other IDT electrode, each of the bus bars of the pair of IDT electrodes having a slotted portion configured on an upper surface of the bus bars opposite to a lower surface contacting the substrate such that at least one hollow within each of the bus bars is opened at least at the upper surface of each of the bus bars, and a dielectric film covering the pair of IDT electrodes, at least a portion of the dielectric film filling in the at least one hollow of each of the bus bars.