Double-dot charge transport in Si single electron/hole transistors
  We studied transport through ultra-small Si quantum dot transistors fabricated from silicon-on-insulator wafers. At high temperatures, 4K<T<100K, the devices show single-electron or single-hole transport through the lithographically defined dot. At T<4K, current through the devices is characterized by multidot transport. From the analysis of the transport in samples with double-dot characteristics, we conclude that extra dots are formed inside the thermally grown gate oxide which surrounds the lithographically defined dot. 
L.P. Rokhinson, L.J. Guo, S.Y. Chou and D.C. Tsui