Patent ID: 11902741
Assignee: nan
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H  B | IPC B  H

Claim 8:
9. A method to fabricate a capacitive micro-electromechanical transducer, the method comprising:
forming a mesa diaphragm in a layer of a first substrate, the mesa diaphragm spanning a first cavity in at least a second layer of the first substrate, the first cavity open at an exterior surface of the first substrate, the exterior surface opposed to an interior surface of the first substrate;
providing a second substrate having an interior surface, an exterior surface, and a second cavity formed in the interior surface of the second substrate, the second cavity having a second opening and terminating in a cavity bottom surface, the cavity bottom surface being non-planar across at least one lateral or radial dimension thereof;
attaching the interior surface of second substrate to the interior surface of the first substrate with the mesa diaphragm in registration with the second cavity and with the mesa diaphragm oscillatable along a longitudinal axis at least partially into the second cavity; and
patterning the cavity bottom surface, which includes forming a plurality of stepped regions such that a depth of the second cavity as measured from the second opening to the cavity bottom surface increases as the cavity bottom surface is laterally or radially traversed from a perimeter thereof to a center thereof.