A simple approach for the fabrication of ultrafast unipolar diodes

Recently a nanoscale unipolar rectifying diode based on electrostatic effects, so called self-switching diode (SSD), was presented in (Song et al., 2003). The main advantage of this device is that it can be fabricated with a simple single-step lithographic process so that its size can be easily reduced to the nanometer-range. This fact, together with the intrinsically high electron velocity of InGaAs channels, should permit the fabrication of devices working in the THz range. Indeed, the high frequency performance of SSDs can be dramatically boosted thanks to a much shorter transit time, due not only to a smaller channel length but also to an enhanced electron velocity associated to ballistic transport. In this work we will make use of a semiclassical 2D Monte Carlo (MC) simulator (employed previously to successfully model other nano-scaled ballistic devices ) to optimize the high frequency performance of SSDs.