Köymen, HayrettinAhiska, Y.Atalar, AbdullahKöymen, I.Taşdelen, A .SinanYılmaz, Mehmet2021-01-282021-01-2820209781728154480http://hdl.handle.net/11693/54950Date of Conference: 7-11 September 2020Conference name: 2020 IEEE International Ultrasonics Symposium, IUS 2020The design and production of a CMOS compatible, watertight and ingress-proof CMUT (capacitive micromachined ultrasonic transducer) microphone, mic-in-CMOS, with vacuum-gap is described. We present an analytical model-based approach for the design of mic-in-CMOS, where a basis for quantitative comparison of performance trade-offs is provided. The sealed vacuum gap of the mic-in-CMOS is basically a lossless sensor, free of mechanical noise. Its SNR is determined by the noise of the pre-amplification electronics (the noise contributor in a CMUT with vacuum gap is essentially the radiation resistance, which is less than 0 dBA for audio band for a 1 mm2 device). The design of mic-in-CMOS involves many multilateral trade-offs such as gap height vs membrane thickness vs sensitivity vs need for linear operation vs bias voltage and atmospheric depression, to name few. The mic-inCMOS design can be mass produced using CMOS film stacks only, as such the fabrication process can be carried out entirely in a CMOS processes production line complemented with CMOS compatible post-processing approaches. Mic-inCMOS has the advantage of low production cost with minimal packaging requirement and on-die EMI / EMC.EnglishCapacitive microphoneSealed gapMEMSCMUTCMOSConference Paper10.1109/IUS46767.2020.9251557