MOS Integrated MEMS Structure for Bio-sensing

Abstract

Biosensors are used to identify analytes such as DNA molecules, proteins or micro-organisms. These devices couple a biological recognition element (the probe) with a physical transducer to generate an observable signal. The work presented here shows a cantilever embedded MOSFET (Metal oxide semiconductor field effect transistor) structure for biosensing. The main features of the structure are piezoelectric actuation/sensing and MOSFET based readout making it suitable for parallel array operation in conjunction with phase coding schemes. The integration of MEMS (Micro electro mechanical systems) structure with CMOS (Complementary MOS) fabrication process also leads to realizability of the system on a chip. The proposed structure has detection capability in sub-picogram range. A CMOS compatible fabrication process flow has also been suggested in this paper along with two different phase coding schemes for noise cancellation.