MEMS Device with Acoustic Leak Control Features

A method of forming a microelectromechanical system (MEMS) microphone comprising:

• forming a backplate;
• forming a back cavity so as to be aligned with the backplate;
• forming at least one post such that the at least one post extends from the backplate downwardly toward the back cavity;
• forming a membrane so as to be positioned between the backplate and the back cavity, the membrane including an inner portion and an outer portion;
• defining a gap with a planar portion of the inner portion and the backplate;
• defining a spring arm in the outer portion, the spring arm positioned to be supported by the at least one post;
• forming a first leak path between the back cavity and the first gap between the inner portion and the spring arm;
• forming a second leak path between the back cavity and the first gap between the spring arm and the back cavity;
• and
• forming a first leak path constriction so as to provide a desired acoustic leakage through at least one of the first leak path and the second leak path.