A micromachined acoustic transducer comprising a parylene diaphragm
piezoelectric transducer. The parylene diaphragm has far lower stiffness
than the silicon nitride. The method for fabricating the parylene
diaphragm acoustic transducer utilizes a prestructured disphragm layer
utilizing silicon nitride which is compatible with high temperature
semiconductor process. A silicon nitride layer is patterned and partially
removed after forming the parylene diaphragm layer in order to enhance the
structural qualities of the parylene diaphragm. The diaphragm may be flat
or dome-shaped.
