Redesign of 180nm CMOS-MEMS sensors and interface for bioinspired processing

CMOS-MEMS capacitive resonant pressure sensor and accelerometer are a state-of-the-art technology in the field of pressure and acceleration sensing, which have demonstrated superior performance compared to other types of sensors. Their development faces challenges related to BEOL integration and manufacturability, which require careful design and fabrication processes. Despite these challenges, CMOS-MEMS sensors offer a number of advantages, such as high sensitivity, low power consumption, and compatibility with standard CMOS processes. They have been implemented in a variety of applications, including atmospheric pressure or acceleration sensing, and are expected to continue to be refined and optimized in the future. This work has the aim to discuss the most important and general aspects related to sensors made with CMOS-MEMS technology, leading the way through the most interesting design characteristics of the CMOS-MEMS Capacitive resonant pressure sensor and Accelerometer. The most important aspects of these sensors, from their simulations with COMSOL to the ease of the migration process from one technology to another will be discussed. Particularly, chapter 1 provides a general introduction stating the state of the art of CMOS-MEMS sensors. Chapter 2 covers the most general aspects of the resonant pressure sensors and accelerometer, from their integration to the manufacturing issues related to the BEOL with emphasis on their theoretical behaviour; some initial simulations performed in COMSOL 5.5 will be carried out on a 250 nm IHP resonant pressure sensor with the aim to set a methodological approach for the development and characterization of further simulations; subsequently, both the 180nm resonant pressure sensor and accelerometer designs already developed in TSMC, will be migrated in UMC technology, hence demonstrating the versatility of CMOS integrated MEMS; additionally, in order to check the reliability of the new born designs, the DRC related to the UMC technology will be performed and the concept of expected errors from the DRC, layout grid technology limitations, and even more, will be deepen in Chapter 3. Chapters 4, 5 and 6 detail the implementation and the simulation of the pressure sensor and the accelerometer performed in COMSOL 5.5; different conditions are discussed for each sensor, distinguishing from the post and pre-fabrication case of each sensor and detailing the analysis with the effect of the squeeze film damping that acts on the central resonators of the various structures. In particular, the fringing fields effect on the accelerometer is briefly discussed in chapter 6. Chapter 7 provides a comparison between the mechanical differences present between the two sensors. An alternative design of the accelerometer with new arrangement of springs made in UMC technology and the consequent sensing properties are proposed in Chapter 8. Finally, in Chapter 9 an overview of the comparison between the different transistors belonging to the different technologies will be exploited for the migration of an operational amplifier from TSMC to UMC with the aim to obtain the most similar characteristics in terms of Loop gain, noise, phase margin and power consumption with respect to the original design. Finally, both the DRC and the LVS check will be performed in Cadence on the UMC operational amplifier in order to validate its functionality and its implementation in the Address Event Representation (AER) field.