Single-Electron Tunneling Transistors Utilizing Individual Dopant Potentials

Abstract

For many decades since the invention of the transistor in 1947, the dimensions of transistor channels have been continuously downscaled so that more and more functionality can be incorporated into one chip. However, nowadays, critical dimensions of transistors enter into the real nanoscale and fundamental limitations, in physics and technology, raise serious challenges in front of further miniaturization. A conceptually different operation mechanism for the next-generation transistors must be considered. In this framework, we focus on transport characteristics arising from single-electron tunneling via individual dopant atoms, the basic operation mode of single-dopant transistors. Single-dopant transistors are devices that make use of individual dopant potentials as natural, ultrasmall quantum dots. In this chapter, we outline basic results related to our research on single-dopant transistors, after briefly introducing the concept and fundamental physics of their operation. First, Kelvin probe force microscopy is used for direct observation of individual dopants in the channel of transistors under normal operation. Next, focus falls on the electrical characteristics indicating single-electron tunneling via individual donor atoms in different temperature ranges. Finally, a domain of dopant-based applications is outlined at the end of the chapter, opening the door for the development of atomic-level electronics.