An integrated MEMS microphone is provided, including, a bonding wafer layer, a bonding layer, an aluminum layer, CMOS substrate layer, an N+ implant doped silicon layer, a field oxide (FOX) layer, a plurality of implant doped silicon areas forming CMOS wells, a two-tier polysilicon layer with selective ion implantation forming a diaphragm, a plurality of implant doped silicon areas forming CMOS source/drain, a gate poly layer forming CMOS transistor gates, said CMOS wells, said CMOS transistor sources/drains and said CMOS gates forming CMOS transistors, an oxide layer embedded with an interconnect contact layer, a plurality of metal layers interleaved with a plurality of via hole layers, a Nitride deposition layer, an under bump metal (UBM) layer and a plurality of solder spheres. Diaphragm is sandwiched between a small top chamber and a small back chamber, and substrate layer includes a large back chamber.