Acoustic transducers with a low pressure zone and diaphragms having enhanced compliance

A MEMS die, comprising;

• a first diaphragm;
• a second diaphragm spaced apart from the first diaphragm such that a cavity is formed between the first diaphragm and the second diaphragm, the cavity having a pressure lower than atmospheric pressure;
• a back plate disposed in the cavity between the first diaphragm and the second diaphragm;
• and
• a stress relieving structure adjacent to a periphery of at least one of the first diaphragm or the second diaphragm, the stress relieving structure comprising a first material embedded between a first diaphragm layer and a second diaphragm layer of at least one of the first diaphragm or the second diaphragm such that the stress relieving structure has a thickness that is greater than a thickness of a portion of the respective first diaphragm or the second diaphragm proximate a center of the respective first diaphragm or the second diaphragm.

A MEMS die, comprising;

• a first diaphragm;
• a second diaphragm spaced apart from the first diaphragm such that a cavity is formed between the first diaphragm and the second diaphragm, the cavity having a pressure lower than atmospheric pressure;
• a back plate disposed in the cavity between the first diaphragm and the second diaphragm;
• and
• a peripheral support structure attached to and supporting at least a portion of a periphery of the first diaphragm and/or the second diaphragm, the peripheral support structure located proximate to, and radially inwards of a peripheral edge of the first diaphragm and the second diaphragm within the cavity, at least a portion of at least one of the first diaphragm or the second diaphragm being radially outwards of the a peripheral edge of the support structure.

A MEMS die, comprising:

• a first diaphragm;
• a second diaphragm spaced apart from the first diaphragm such that a cavity is formed between the first diaphragm and the second diaphragm, the cavity having a pressure lower than atmospheric pressure;
• a plurality of openings defined in the second diaphragm, the plurality of openings sealed with a plug of a sealing material;
• a plurality of catch structures coupled to the second diaphragm proximate to a corresponding opening of the plurality of openings and disposed within the cavity, each of the plurality of catch structures comprising a ledge extending beneath the corresponding opening such that a portion of the plug of the sealing material is disposed on the ledge;
• and
• a back plate disposed in the cavity between the first diaphragm and the second diaphragm;
• and

A MEMS die, comprising;

• a first diaphragm;
• a second diaphragm spaced apart from the first diaphragm such that a cavity is formed between the first diaphragm and the second diaphragm, the cavity having a pressure lower than atmospheric pressure;
• and
• a back plate disposed in the cavity between the first diaphragm and the second diaphragm, the back plate layer comprising an insulating layer interposed between two conductor layers.