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Autori: E. Hamid, D. Moraru, Y. Kuzuya, T. Mizuno, L. T. Anh, H. Mizuta, and M. Tabe
Editorial: Physical Review B, 87 (8), p.085420, 2013.
Individual dopant atoms in silicon devices gain active roles as channel dimensions move into nanoscale from source to drain. A single donor can work as an atomic quantum dot, mediating single-electron tunneling transport. However, tunneling operation of single-donor transistors has so far been reported only at low temperatures below ~15 K, mainly because the tunnel barriers coupling the donor to the leads are too low. For higher-temperature operation, the donor’s tunnel barriers must be considerably higher than kBT. Here, we use a special design of a nanoscale Si channel with a central stub region, in which a phosphorus donor’s ground state becomes deeper due to dielectric confinement effect. In these stub-channel devices, electron tunneling via one donor atom survives even at temperatures above 100 K. Results of ab initio atomistic simulations of single-donor nanostructures support our experimental findings.
Cuvinte cheie: single donor, silicon nano-transistor, dielectric confinement