Effects of discrete quantum levels on electron transport in silicon single-electron transistors with an ultra-small quantum dot

We analyze electron transport of silicon single-electron transistors (Si SE Ts) with an ultra-small quantum dot using a master-equation model taking in to account the discreteness of quantum levels and the finiteness of scatter ing rates. In the simulated SET characteristics, aperiodic Coulomb blockade oscillations, fine structures and negative differential conductances due t o the quantum mechanical effects are superimposed on the usual Coulomb bloc kade diagram. These features are consistent with the previously measured re sults. Large peak-to-valley current ratio of negative differential conducta nces at room temperature is predicted for Si SETs with an ultra-small dot w hose size is smaller than 3 nm.