Silicon single-electron devices

Single-electron devices (SEDs) are attracting a lot of attention because of their capability of manipulating just one electron. For their operation, they utilize the Coulomb blockade (CB), which occurs in tiny structures made from conductive material due to the electrostatic interactions of confined electrons. Metals or III-V compound semiconductors have so far been used to investigate the CB and related phenomena from the physical point of view. However, silicon is preferable from the viewpoint of applications to integrated circuits because, on a silicon substrate, SEDs can be used in combination with conventional complementary metal-oxide-semiconductor (CMOS) circuits. In addition, the well established fabrication technologies for CMOS large-scale integrated circuits (LSIs) can be applied to making such small structures. LSI applications of the silicon SEDs can be categorized into two fields: memory and logic. Many kinds of device structure and fabrication process have been proposed and tested for these purposes. This paper introduces the current status of silicon-based SED studies for LSI applications.