(Invited) Effect of Individual Dopants in Nano-SOI-MOSFETs and Nano-pn-Diodes

Abstract

Recently, individual dopant atoms have been utilized as naturally-created quantum dots (QDs) that allow the control of single-carrier tunneling transport in field-effect transistors (FETs), typically at low temperatures. It has been also reported that a few coupled-dopants can form a relatively larger and more complex QD, which may be, however, more practical than a single-dopant QD in terms of fabrication processes and/or elevated-temperature operation. Such discreteness of dopants in nanostructures, down to the level of individuality of dopants, has been observed not only in FETs, but also in nanoscale pn-diodes. Here, we outline results of single-electron tunneling transport via donors in FETs in the regime of low concentration (individual donors) and high concentration (clustered or coupled donors). We also show basic results of current enhancement in low-dimensional Esaki diodes due to tunneling through dopants. Finally, observation of dopant potentials by Kelvin probe force microscopy is described.