Characteristics of silicon-on-insulator single-electron transistors with electrically induced tunnel barriers

Abstract

Single-electron transistors with a side gate structure were fabricated on SOI (silicon-on-insulator) substrate. The silicon channel in which electrons could be transported was defined by electron-beam lithography, and the channel was wrapped by two side gates which could control the electrically induced tunnel barrier. The electrical characteristics of the fabricated device were measured at 4.2 K. The measured characteristics showed a larger current oscillation period and amplitude than those estimated from the structural parameters. Also, the current contour plot showed irregular Coulomb diamonds with different sizes. These characteristics are the result of multi-dot formation. A Monte-Carlo simulation verified that these multi-dot characteristics result from unintentional quantum dots due to the irregularity of electron-beam lithography.