CMOS-compatible MEMS processes and their application to the development of biosensors

The research activity developed during my Ph.D. program was focused on CMOS-compatible MEMS (Micro-Electro-Mechanical System) processes and their application to the development of biosensors. A first activity has been oriented towards the development of a technique to reduce the etching times and increase the freedom in the design of large suspended microstructures fabricated by bulk anisotropic etching of silicon. This goal was obtained by pre-patterning of the membrane with periodic convex-corner patterns. Different periodic patterns are proposed and analyzed, experimental release times for dielectric membranes are presented. The second activity research was focused on the design and fabrication improvement of a magnetically actuated microbalance for biosensing application. A CMOS-compatible protocol for covalent bonding of organo-functional silanes (to be used as link sites for biomolecular probes) on the microbalance surface was developed. The functionality of the device as a gravimetric sensor was verified. Moreover, a single chip integrated electronic oscillator based on the MEMS resonator was designed. A first prototype of circuit was implemented and characterized.