Co-integrated bulk acoustic wave resonators

A method for fabricating an electrical circuit assembly, comprising:

• forming a first lateral-mode resonator upon a semiconductor integrated circuit, the semiconductor integrated circuit comprising one or more transistor structures, the forming the first lateral-mode resonator comprising:
• forming an acoustic energy storage layer;
• forming a piezoelectric layer acoustically coupled to the acoustic energy storage layer;
• forming a conductive region electrically coupled to piezoelectric layer and electrically coupled to the semiconductor integrator circuit;
• and
• functionalizing a portion of the first lateral-mode resonator including forming a first functionalized layer configured to interact with a first species in proximity to the first lateral-mode resonator in a manner altering a mass of the lateral-mode resonator in the presence of the first species.

An electrical circuit assembly, comprising:

• a semiconductor integrated circuit comprising one or more transistor structures;
• and
• a first lateral-mode resonator fabricated upon a surface of a semiconductor integrated circuit, the first lateral-mode resonator comprising:
• an acoustic energy storage layer;
• a piezoelectric layer acoustically coupled to the acoustic energy storage layer;
• and
• a first conductive region electrically coupled to the piezoelectric layer and electrically coupled to the semiconductor integrated circuit;
• and
• a dielectric region located upon a surface of the semiconductor integrated circuit,
• the dielectric region coupled to the acoustic energy storage layer and defining a cavity between the acoustic energy storage layer and the semiconductor integrated circuit;
• wherein the acoustic energy storage layer includes a released configuration suspended from h dielectric region;
• wherein the dielectric region is mechanically coupled to the acoustic energy storage layer using multiple tether structures, the multiple tether structures comprising respective tether structures located in respective regions along the first lateral-mode resonator corresponding to respective nodes where mechanical displacement of a suspended portion of the resonator is suppressed or inhibited when a suspended portion of the first lateral-mode resonator resonates according to a lateral acoustic mode;
• and
• wherein the semiconductor integrated circuit and the first lateral-mode resonator form an oscillator circuit to provide an oscillation frequency established at least in part by the first lateral-mode resonator.