Inertial sensing MEMS device using a floating-gate MOS transistor as transducer by means of modifying the capacitance associated to the floating gate

Abstract

In this work, a novel application of floating gate MOS transistors is presented. An inertial sensor with an embedded FGMOS was designed, simulated and fabricated using commercially available CMOS technology, like the ON Semiconductor 0.5 µm, two poly, three metal, N-well, post-processed using a surface micromachining etchant to obtain a CMOS-MEMS chip, and tested. COMSOL multiphysics was used for electro-mechanical evaluation of the inertial system, PSPICE for electrical behavior analysis, Keithley instruments for electrical characterization, and Labview for data acquisition for electrical characterization. In this work, it is demonstrated that an embedded FGMOS can be used to correlate drain current either for static or dynamic inertial parameters. The presented work demonstrates the feasibility to change the coupling coefficient of the FGMOS by means of a MEMS structure, like an accelerometer, to convert displacement into an electrical signal, being suitable for integration in more complex systems.