Classical and Quantum Comparison of the High-frequency Transconductance of Nanoscale Field Effect Transistors

In order to provide accurate predictions for state-of-the-art devices, the quantum mechanical (QM) theory gradually upgrades (by including concepts such as tunnelling, quantization,..) the different approaches used for modelling electron transport. Recently, CMOS has been demonstrated to be a viable technology for very-high-bit-rate broadband and wireless communication systems up to 40 Gb/s and 50 GHz [1]. Therefore, a study of the novel effects that the QM theory can introduce on the performance of phase-coherent devices driven at high frequencies, f, comparables to the inverse of the electron transit time, seems mandatory. In this work, we compare the classical and quantum small-signal admittance parameters for a nanoscale double gate MOSFET with an intrinsic channel of L=15 nm length and t=2nm width, that provides transport through a two-dimensional (2D) electron gas, (see fig. 1).