Patent ID: 8404132

Claim:
A process for making a membrane having curved features, comprising: vacuum bonding a first surface of a first substrate to a first surface of a first membrane layer, the first surface of the first substrate having a plurality of cavities formed therein, the first membrane layer being an exposed layer of a second substrate, a second surface of the first membrane layer being attached to a handle layer of the second substrate, and the first surface of the first membrane layer seals the plurality of cavities to form a plurality of vacuum chambers at completion of the vacuum bonding; removing the handle layer of the second substrate to expose the second surface of the first membrane layer; exposing the second surface of the first membrane layer to a fluid pressure such that the first membrane layer bends in areas above the plurality of cavities and touches respective bottom surfaces of the plurality of cavities at a plurality of respective contact locations; and annealing the first membrane layer and the first substrate to form bonds between the first membrane layer and the first substrate at the plurality of respective contact locations.