Capacitive micromachined ultrasound transducer and methods of making the same

A method of making a capacitive micromachined ultrasound transducer cell, comprising:

• providing a carrier substrate having a first surface and a second surface, wherein the carrier substrate comprises glass;
• forming a via in the carrier substrate, wherein the via extends from the first surface to the second surface of the carrier substrate;
• and
• coupling a membrane to the carrier substrate to define an acoustic cavity, wherein a depth of the acoustic cavity is defined by support posts, and wherein one of the carrier substrate, or the membrane comprises the support posts.

A method of making a capacitive micromachined ultrasound transducer array, comprising

• providing a glass substrate having a first surface and a second surface, wherein the first surface is partitioned into a plurality of portions;
• forming vias in the glass substrate, wherein the vias extend from the first surface of the glass substrate to the second surface of the glass substrate;
• depositing bottom electrodes on each of the portions of the first surface of the glass substrate;
• coupling a plurality of membranes to the glass substrate such that each membrane is coupled to a portion of the glass substrate to define an acoustic cavity, and wherein a depth of the acoustic cavity is defined by support posts disposed within one of the glass substrate, or the membrane;
• and
• depositing contact pads on the first surface of the glass substrate such that the contact pads are formed on the portions of the glass substrate which does not employ the acoustic cavity, and wherein each contact pad is in electrical communication with a corresponding via.

A system, comprising:

• a transducer array comprising a plurality of capacitive micromachined ultrasound transducer cells, each cell comprising:
• a glass substrate having a first surface and a second surface;
• a membrane bonded to the first surface of the glass substrate, wherein one of the first surface of the glass substrate or the membrane comprises support posts, and wherein the glass substrate, the membrane and the support posts define a cavity;
• an electrically insulating layer disposed in the cavity and coupled to the first surface of the glass electrode;
• and
• a bottom electrode disposed in the cavity.