A novel floating-gate biosensing device with controlled charge-modulation

A novel charge-modulated biosensing device is proposed. The basic architecture of an extended floating-gate field-effect transistor (FET) is modified for VLSI applications. The floating-gate is umbrella-shaped (UGFET), maximizing the charge sensing area in a much reduced device area. Compared to previous extended floating-gate structures, the UGFET shows improved scalability and sensitivity. Extensive device simulations validate the UGFET model. The design is fabricated in a standard CMOS process and characterized with electrolytes and charged solutions. Transconductance measurements confirm its high sensitivity and workability.