Room-temperature single-electron tunneling in highly-doped silicon-on-insulator nanoscale field-effect transistors

From the viewpoint of high- (room-) temperature operation of donor-based single-electron transistors, we make a comparative study of nano-scale silicon-on-insulator transistors with phosphorus-doped channels for two dopant-concentration regimes: N (D) approximate to 1 x 10(18) and 2 x 10(20 )cm(-3). We experimentally show that the high-N (D) devices can provide room-temperature single-electron tunneling operation owing to a large tunnel-barrier height, while operation temperature is limited to about 100 K for the low-N (D) devices. Numerical simulations of random donor-atom distributions indicate that donor clustering plays a dominant role in the formation of quantum dots, and suggests that clusters comprising of more-than-three donors are responsible for room-temperature operation.