Stacked resonators with shared reflector layers

A resonator structure, comprising:

• a first resonator;
• and
• a second resonator, which is vertically stacked with the first resonator and shares a common reflector with the first resonator, wherein:
• the common reflector is a conductive reflector and includes top common vias, bottom common vias, a top common dielectric layer, a bottom common dielectric layer underneath the top common dielectric layer, and alternating high acoustic impedance layers and low acoustic impedance layers residing vertically between the top common dielectric layer and the bottom common dielectric layer;
• the first resonator is at least composed of a first top electrode, a first piezoelectric layer underneath the first top electrode, a first bottom electrode underneath the first piezoelectric layer, and the common reflector underneath the first bottom electrode;
• the second resonator is at least composed of the common reflector, a second top electrode underneath the common reflector, a second piezoelectric layer underneath the second top electrode, and a second bottom electrode underneath the second piezoelectric layer;
• each of the top common vias extends through the top common dielectric layer and electrically connects the first bottom electrode and a top one of the high acoustic impedance layers, and each of the bottom common vias extends through the bottom common dielectric layer and electrically connects the second top electrode and a bottom one of the high acoustic impedance layers;
• and
• the first resonator and the second resonator are acoustically isolated from each other.

A resonator structure comprising:

• a first resonator;
• a second resonator, which is vertically stacked with the first resonator and shares a common reflector with the first resonator;
• and
• a third resonator, which is vertically stacked with the first resonator and the second resonator, and shares a second common reflector with the second resonator, wherein:
• the first resonator is at least composed of a first top electrode, a first piezoelectric layer underneath the first top electrode, and the common reflector underneath the first piezoelectric layer;
• the second resonator is at least composed of the common reflector, the second piezoelectric layer underneath the common reflector, the second bottom electrode underneath the second piezoelectric layer, and the second common reflector underneath the second bottom electrode;
• the third resonator is at least composed of the second common reflector, a third piezoelectric layer underneath the second common reflector, and a third bottom electrode underneath the third piezoelectric layer;
• and
• the first resonator, the second resonator, and the third resonator are acoustically isolated from each other.