The present invention relates to a
CMOS compatible
MEMS microphone, comprising: an
SOI substrate, wherein a
CMOS circuitry is accommodated on its
silicon device layer; a
microphone diaphragm formed with a part of the
silicon device layer, wherein the
microphone diaphragm is doped to become conductive; a
microphone backplate including
CMOS passivation layers with a
metal layer sandwiched and a plurality of through holes, provided above the
silicon device layer, wherein the plurality of through holes are formed in the portions thereof opposite to the microphone diaphragm, and the
metal layer forms an
electrode plate of the backplate; a plurality of dimples protruding from the lower surface of the microphone backplate opposite to the diaphragm; and an air gap, provided between the diaphragm and the microphone backplate, wherein a spacer forming a boundary of the air gap is provided outside of the diaphragm or on the edge of the diaphragm; wherein a back hole is formed to be open in substrate underneath the diaphragm so as to allow sound pass through, and the microphone diaphragm is used as an
electrode plate to form a variable
capacitive sensing element with the
electrode plate of the microphone backplate.