The kink-related excess low-frequency noise in silicon-on-insulator MOST´s

The phenomenology of the kink-related low-frequency (LF) noise overshoot in partially depleted (PD) silicon-on-insulator (SOI) MOS transistors is described in detail. The influence of various physical parameters is reported. Based on the observations, a comprehensive first-order theory for the feature is derived. The model is based on the charge fluctuations which are caused by deep-level assisted generation-recombination events in the depletion region of the transistor. It will be shown that the noise amplitude is proportional to the density of deep-level centers, while the peak position is a sensitive function of the saturation voltage. This follows from the postulated dependence of the capture time on the inverse substrate current. As will be shown, the standard expression for the multiplication current is in first order also valid for SOI MOST´s, both at room temperature and at 77 K. Simulations demonstrate that the proposed model correctly predicts the dependence of the noise overshoot on the measurement frequency, on the gate voltage, the temperature and on the device length. Finally, the spectroscopic potential of the feature will be outlined and possible ways to render the technique truly quantitative are pointed out