Ultrasonic device

Abstract

An ultrasonic device includes a substrate having an opening portion penetrating through the substrate in a thickness direction; a membrane formed on the substrate and having a movable film defining a top surface portion of the opening portion; a lower electrode formed on a front surface of the membrane at a side opposite the opening portion; a piezoelectric film formed on a front surface of the lower electrode at a side opposite the membrane; and an upper electrode formed on a front surface of the piezoelectric film at a side opposite the lower electrode, wherein the movable film of the membrane has a shape that is deflected so as to be convex toward the lower electrode, and wherein the lower electrode is an IrOx/Ir/Ti/Pt laminated film with which an IrOx film, an Ir film, a Ti film, and a Pt film are laminated in that order from the membrane.

Dependencies are inferred from the claim text.