In IUS 2016, we proposed a capacitive micromachined ultrasonic transducer embedded a field effect transistor (CMUT-FET) for 20 MHz operation. As a result, the possibility of high sensitivity in a high-frequency range was verified via a combination of two simulation tools, a 3-D finite element analysis (FEA) for the CMUT part and a technology computer aided design for the FET part. Since the results were acquired from the separate models, the exact voltage drop of the channel capacitance in the FET part was not considered into the CMUT simulation part. In this paper, we suggest a full analytic model which can simulate the whole CMUT-FET model with high accuracy and fast computation. As a consecutive work, we also report on a fabrication process of the CMUT-FET with nickel silicide source/drain contacts and low-temperature wafer bonding. Since high-temperature process on the upper CMUT during direct wafer bonding critically affects the performance of the lower FET, several low-temperature direct wafer bondings were attempted and the results were demonstrated in this paper.