Electron-tunneling operation of single-dopant-atom transistors at elevated temperature - Toward room temperature operation

摘要

Single-dopant transistors work based on single-electron tunneling via an individual dopant atom located in a nanoscale channel. Until recently, single-dopant transistors have been studied only at low temperatures (<15 K) in order to clarify the fundamental properties of dopants in nano-channels. At higher temperatures, tunneling via dopants may be smeared out because of thermally-activated carriers. However, it is important to design single-electron tunneling single-dopant devices that work even at elevated temperatures. In this work, we show that the tunnel barrier can be increased by special design of the channel shape to enhance the dielectric confinement effect. This allows the observation of tunneling current peaks even at temperatures of about 100 K, much higher than reported so far. Ab initio simulations offer further insights into the basic properties of individual dopants in extremely downscaled channels. The results suggest the possibility of realizing single-dopant transistors operating by tunneling even at room temperature.