A capacitative pressure sensor that has a silicon substrate, CMOS layers deposited on the silicon substrate, a conductive layer deposited on the CMOS layer and, a passivation layer on the conductive layer. A conductive membrane extends from the substrate assembly such that it is spaced from the conductive layer. The conductive layer has a plurality of apertures and the silicon substrate to define a passage for fluid communication with fluid pressure exterior to the pressure sensor and a cap extending from the substrate assembly to cover the membrane and form a chamber on one side of the conductive membrane that is sealed from the fluid pressure exterior to the pressure sensor.