Random telegraph noise in ultimate MOSFETs at very low temperature in the subthreshold regime

We study electronic transport and current noise in 50nm gate length PMOSFETs at very low temperature (T<1K). In the linear regime the drain source current versus gate voltage below the threshold voltage exhibits reproducible sharp resonances due to coherent transport through the disordered channel. We present first experiment showing the time dependence of these resonances particularly the amount of random telegraph and 1/f noise which affect the resonance pattern. Implications for sensitive electrometry are discussed.