Room temperature Coulomb blockade and low temperature hopping transport in a multiple-dot-channel metal-oxide-semiconductor field-effect-transistor

We have investigated the transport properties of an extremely narrow channel metal-oxide-semiconductor field-effect-transistor (MOSFET) fabricated by a novel anisotropic etching technique. The device shows clear Coulomb blockade oscillations at room temperature, while aperiodic sharp peaks are observed at low temperatures. Measurements of temperature dependence and magnetic field dependence reveal that the narrow channel of the MOSFET is separated into quantum dots and that not only the resonant tunneling transport but also the thermally activated hopping conduction plays an important role at low temperatures.