Terahertz ultra-fast single-electron transistors fabricated on silicon-on-insulator structures by pattern-dependent oxidation

We report a successful fabrication of silicon-based single-electron transistors (SETs), which display nearly THz-level ultra-fast intrinsic RC speed. The SETs were fabricated on silicon-oxide-insulator structures by a pattern-dependent oxidation (PADOX) technique, combined with e-beam lithography. Drain conductances measured at 4.2 K approach large values of muS order, exhibiting Coulomb oscillations with peak-to-valley current ratios much greater than1000. Data analysis, with the probable mechanism of PADOX, yields their intrinsic RC speeds of similar to1.3 THz, which is within an order of magnitude of the theoretical quantum limit. Even though a direct dynamical quantity related to the extracted RC time constant is not directly measured, this result will be of importance to the mesoscopic transport and high-frequency communities.