Non-Gaussian fluctuation in the charge transport of Si nanochains

The stability of the tunneling charge transport of a tangle of Si nanochains is investigated at high bias voltages using a micromanipulator in a scanning electron microscope. We confirm that the influence of electron injection due to the electron beam of a scanning electron microscope on the charge transport properties of nanochains is negligible when the electrode gap is small and the bias voltage is large. Under such conditions, current - time curves show large fluctuations. We find that the fluctuation is not a simple Brownian motion, but its distribution function can be fitted well by a Levy distribution. Its origin is discussed in terms of percolation theory.