Flexible capacitive ultrasonic transducer and method of fabricating the same

A method for fabricating capacitive ultrasonic transducers, the method comprising:

• providing a substrate;
• forming a flexible layer on the substrate;
• forming a first conductive layer on the flexible layer;
• forming a patterned sacrificial layer on the first conductive layer;
• forming a first polymer layer over the patterned sacrificial layer;
• patterning the first polymer layer to provide a patterned first polymer layer, exposing portions of the patterned sacrificial layer through openings;
• forming a second conductive layer on the patterned first polymer layer;
• patterning the second conductive layer to provide a patterned second conductive layer;
• forming a second polymer layer over the patterned second conductive layer;
• patterning the second polymer layer, exposing portions of the patterned sacrificial layer through the openings;
• and
• removing the patterned sacrificial layer through the openings.

A method of forming capacitive ultrasonic transducers, the method comprising:

• forming a flexible layer on a substrate;
• forming a first conductive layer on the flexible layer;
• forming a patterned metal layer on the first conductive layer;
• forming a first polymer layer on the patterned metal layer and the first conductive layer;
• patterning the first polymer layer to provide a patterned first polymer layer, exposing portions of the patterned metal layer through openings;
• forming a patterned second conductive layer on the patterned first polymer layer;
• forming a patterned second polymer layer on the patterned second conductive layer and the patterned first polymer layer over the patterned metal layer;
• and
• removing the patterned metal layer through the openings.