Micromachined ultrasonic transducer with air-backed cavity and electrical connection
A method and associated apparatus directed to a piezoelectric micromachined ultrasonic transducer (pMUT) defining an air-backed cavity are provided. A first via defined by a device substrate and associated dielectric layer, and extending to the first electrode, is substantially filled with a first conductive material. A support member engaged with the device substrate defines a second via extending to the first conductive material. The second via has a second conductive material disposed thereon, forms an electrically-conductive engagement with the first conductive material, and extends outwardly of the second via to be accessible externally to the support member. A connective element extends through a third via defined by a connection support substrate and is in electrically-conductive engagement with the second conductive material, wherein one of the connective element and connection support substrate is bonded to one of the support member and second conductive material by a bonding material engaged therebetween.