Quantum Channel FETs for Advanced Biosensors

Highly sensitive high-speed biosensors are key devices for precise diagnostics, which allows the application of medical treatment in a short time. In this paper, noise spectra and characteristic time constants are studied in nanotransistors with channel sizes below 30[Formula: see text]nm. The quantization effect due to the formation of a quantum dot channel is analyzed based on the transport and noise properties of the device structures. Ultra-low flicker noise at the quantum level with a Hooge parameter of about 10[Formula: see text] is registered. A strong dependence of the characteristic switching time on the modulation effect is revealed with a slope ([Formula: see text]) that considerably exceeds the value of 1, which is typically obtained in large-area device structures. This reflects the fact that a 700% amplification of sensitivity in nanotransistor biosensors can be obtained. A dimensionless R-factor introduced by the ratio of the emission time constant to the capture time constant as a function of gate voltage reveals a slope equal to 20, which is promising for the extraction of very small signals from biomolecules with 20 times higher sensitivity.