Co-tunneling current in very small Si single-electron transistors

A very small Si single-electron transistor (SET) was fabricated by converting a one-dimensional Si wire on a SIMOX substrate into a small Si island with a tunneling barrier at each end by means of pattern-dependent oxidation. The conductance characteristics of the device are very stable and do not change after thermal cycles between low and room temperatures. The temperature and voltage dependence of the cotunneling current measured with high accuracy are analyzed in comparison with inelastic cotunneling theory.