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We have numerically studied the single-charge transfer operation in two-dimensional (2D) random-multidot-channel field-effect transistors (FETs) using orthodox theory of the Coulomb blockade phenomenon. The randomness of the multidot structure is reflected in the gate capacitance (Cg) in the equivalent circuit, embodying the dot-size disorder of the realistic devices developed in our laboratory. It was found that “turnstile operation” meaning that individual electron is transferred one by one from the source to the drain with a cycle of an alternating gate voltage can be performed in both random and homogeneous 2D multidot-channel FETs, although their equivalent circuits are significantly different from the ordinary four-junction turnstile device. By increasing the Cg randomness, some devices show that the average gate and drain bias condition (Vg0,Vd) which allows the turnstile operation is more relaxed. Consequently, the random-multidot-channel FET can work as a single-electron turnstile device. [ABSTRACT FROM AUTHOR]

We study interaction of single-electron current and incident photons in nanometer-scale phosphorus-doped silicon-on-insulator field-effect transistors. Trapping events of a photoexcited-electron by a trap donor are observed as random telegraph signals in single-electron-tunneling current flowing through a current-path donor. Trapping causes a potential change at the current-path donor, inducing a current change. An opposite current change is caused by electron detrapping from the trap donor to the current-path donor. This indicates that only a few donors (two donors in this study) work in the interaction between single-electron transport and photoexcited-electron trapping, even in the presence of many donors. [ABSTRACT FROM AUTHOR]

We describe single-electron transfer between two donors in thin silicon-on-insulator field-effect transistors with phosphorus-doped channel. At low temperatures, single-electron tunneling through one donor can be identified in source-drain current/gate voltage measurements as a single current peak. On this peak, we observed hysteresis most likely as a signature of single-electron transfer with another donor. The origin of single-electron transfer is related to different intensities of coupling between each donor and the interface, as evidenced from simulations. It was found that donor-interface coupling is essential for the energetic transfer of a single-electron location within the two-donor system. [ABSTRACT FROM AUTHOR]

A two-dimensional dislocation network artificially embedded in a silicon-on-insulator (SOI) layer was examined as the source of lattice strain to generate a periodic potential. A screw dislocation network with the period of 20 nm was formed in an SOI layer using a twist bonding of two SOI wafers. n-channel metal-oxide-semiconductor field-effect transistors using the dislocation-embedded SOI layer showed an oscillation of drain current with the gate voltage at the temperatures below 40 K. This oscillation is ascribed to the single-electron tunneling through the spatially modulated potential. The results suggest that the dislocation network works as the strain source to form the potential array. [ABSTRACT FROM AUTHOR]

Single-hole transport in a two-dimensional Si multidot-channel field-effect transistor is studied. It is found that the single-hole-tunneling current fluctuates in the particular ranges of drain voltage and gate voltage. Such a phenomenon can be explained by a model that the hole transport through the percolation path is sensitively influenced and fluctuates with the time due to charging–discharging and polarity-switching of the dots adjacent to the percolation path. A Monte Carlo simulation using a parallel-double-dot circuit shows good agreement with the experimental characteristics. [ABSTRACT FROM AUTHOR]

Abstract: Single-electron devices are attractive because of their ultimate capabilities such as single-electron transfer, single-electron memory, single-photon detection and high sensitivity to elemental amount of charge. We studied single-electron transport in doped nanoscale-channel field-effect transistors in which the channel potential is modulated by ionized dopants. These devices work as arrays of quantum dots with dimensions below present lithography limits. We demonstrate the ability of dopant-induced quantum dot arrays to mediate the transfer of individual electrons one at a time (single-electron transfer). We also monitored the actual dopant distribution and observed single dopant potentials using low temperature Kelvin probe force microscopy. [Copyright &y& Elsevier]