Charge-based chemical sensors: a neuromorphic approach with chemoreceptive neuron MOS (C/spl nu/MOS) transistors

• Published in: IEEE transactions on electron devices 2003-10, Vol.50 (10), p.2171-2178
• Main Authors: Shen, N.Y.-M., Zengtao Liu, Chungho Lee, Minch, B.A., Kan, E.C.-C.
• Format: Article
• Language: English
• Subjects: Chemical transducers; CMOS; CMOS integrated circuits; Computational fluid dynamics; Devices; Fluid flow; Fluids; Metal oxide semiconductors; Microsensors; Neural network hardware; Semiconductor devices; Transient analysis; Transistors
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2003.816905

A novel chemoreceptive neuron MOS (C/spl nu/MOS) transistor with an extended floating-gate structure has been designed with several individual features that significantly facilitate system integration of chemical sensing. We have fabricated C/spl nu/MOS transistors with generic molecular receptive areas and have characterized them with various fluids. We use an insulating polymer layer to provide physical and electrical isolation for sample fluid delivery. Experimental results from these devices have demonstrated both high sensitivity via current differentiation and large dynamic range from threshold voltage shifts in sensing both polar and electrolytic liquids. We have established electrochemical models for both steady-state and transient analyses. Our preliminary measurement results have confirmed the basic design and operations of these devices, which show potential for developing silicon olfactory and gustatory units that are fully compatible with current CMOS technology.