ABSTRACT
Information processing by transporting carriers in nanoelectronic devices and circuits is severely affected by the breakdown of Ohm’s law when the applied voltage V in a nanoscale (L < 1000 nm) device exceeds the critical voltage Vc = VtL/∙o∞ (V > Vc). Here Vt is the thermal voltage with a value 0.0259 V at room temperature and ∙o∞ (typically 100 nm) is the mfp. This nonohmic behavior is the cause of the current saturation leading to the resistance surge. The saturation arises due to realignment of randomly oriented velocity vectors to the unidirectional streamlined ones in a high electric eld when voltage applied across a resistor exceeds the critical value. The surge accelerates for signal propagation as dc voltage is increased. Both the digital and analog signal processing will be affected by the presence of nonohmic nonlinear behavior. This surge changes the RC time constants, power consumption, and voltage and current division laws. Ballistic processes overpower the scattering-limited transport in a high electric eld and in channels where length is smaller than the scattering-limited mfp. The transient switching delay in a micro-/nanoscale circuit containing resistive and reactive elements is sternly affected by the surge in the resistance arising out of sublinear current-voltage (I-V) characteristics limited to the drift velocity leading to current saturation. The frequency response f = 1/2πτt, where τt is the transit time through the conducting channel and is lower than that predicted from the application of Ohm’s law. The resistance surge boosts the RC time constant and attenuates the L/R time constant dramatically. These results are necessary for extraction of transport parameters and assessing the limitations of parasitic elements in a micro-/nanoscale circuit.
