Multiple type biosensors fabricated using the CMOS BioMEMS platform

This paper reports a CMOS BioMEMS (biological micro-electromechanical system) platform for monolithically integrated multi-type biosensors and readout circuits. Gold is implemented in the current CMOS MEMS platform as an absorption layer for bio targets by wafer-level process tools. The characteristics of the gold and piezoresistive cantilever structures are analyzed. Two kinds of biosensors are fabricated and investigated in this work. The first one is an electro-microchip for immunoassay using platinum nano-particles and silver enhancement, and the detection time is over 10% shorter than the previous example made with a glass platform. The second biosensor is composed of the MIP (molecularly imprinted polymer) and ion-sensitive field-effect transistor (ISFET), and is used to detect creatinine. Moreover, the ring-oscillator-based readout circuit integrated with the ISFET is able to report the creatinine concentration. Two experimental cases demonstrate the possibility of integrating multiple type biosensors and readout circuits in micro or nano systems based on the CMOS BioMEMS platform.