Acoustic wave device and method for manufacturing the same

摘要

An acoustic wave device includes a first electrode film arranged on a top surface of a piezoelectric substrate and defining electrodes including IDT electrodes and a second electrode film arranged to extend from the top surface of the piezoelectric substrate to a portion of a top surface of the first electrode film. The second electrode film defines electrodes including a wiring electrode 9 and pad electrodes and is made of a layered metal film including a plurality of metal films deposited in layers. The lowermost layer of the second electrode film is made of a metal selected from the group consisting of aluminum-copper alloy, nickel-chromium alloy, aluminum-silicon alloy, aluminum-titanium alloy, titanium, and copper, and the lowermost layer of the second electrode film is arranged to extend to a side surface of the second electrode film.

主权项

1. An acoustic wave device comprising:
a piezoelectric substrate; a first electrode film arranged on a top surface of the piezoelectric substrate and defining electrodes including IDT electrodes; and a second electrode film arranged to extend from the top surface of the piezoelectric substrate to a portion of a top surface of the first electrode film; wherein the second electrode film defines electrodes including a wiring electrode and a pad electrode, and the second electrode film is defined by a layered metal film including a plurality of metal films deposited in layers; a lowermost layer of the layered metal film defining the second electrode film includes a metal selected from the group consisting of aluminum-copper alloy, nickel-chromium alloy, aluminum-silicon alloy, aluminum-titanium alloy, titanium, and copper; an upper layer of the layered metal film defining the second electrode film includes a top surface, a bottom surface, and side surfaces that extend between the top surface and the bottom surface; and the lowermost layer of the layered metal film defining the second electrode film is arranged to extend to and cover at least one of the side surfaces of the upper layer of the layered metal film defining the second electrode film.