On the Origin of Negative Differential Conductance in Ultranarrow-Wire-Channel Silicon Single-Electron and Single-Hole Transistors

Abstract

The origin of negative differential conductance (NDC) is investigated in both a silicon single-electron transistor (SET) and single-hole transistor (SHT) with a common ultranarrow wire channel, focusing on the effect of electrically capacitive coupling, for the first time. First, Coulomb blockade oscillations are observed at room temperature by using an n-type/p-type common-ultranarrow-wire-channel metal–oxide–semiconductor field-effect transistor (MOSFET), and it is found that an ultrasmall silicon dot and high tunneling barriers can be formed in the ultranarrow wire channel for both electron carriers and hole carriers. Then, clear NDC due to large quantum confinement in the ultrasmall silicon quantum dot is observed in both the SET and the SHT under opposite bias conditions. Electrically capacitive coupling between the silicon dot and the electrodes through the tunneling barriers strongly controls the occurrence of NDC in both the SET and the SHT.