Resonant tunneling through a single self-assembled InAs quantum dot in a micro-RTD structure

By forming a micron-scale Schottky diode on a GaAs/n(+)-GaAs wafer with low density (similar to 4 x 10(8) cm(-2)) self-assembled InAs quantum dots (QDs) embedded in the top GaAs layer, we have studied resonant tunneling transport of electrons via single QDs. As the diode defined by electron-beam lithography and chemical etching has a size of about 1 mum(2) and the edges of each diode are depleted, the number of active InAs QD contained in each microdiode can be reduced to less than unity in average. Current-voltage measurements were performed using conductive probe atomic force microscope,, and current peaks caused by electrons resonantly tunneling through quantum levels of single QDs have been observed at temperatures as high as similar to 130 K. (C) 2002 Elsevier Science B.V. All rights reserved.