SELF-ORGANIZED GROWTH OF QUANTUM DOT-TUNNEL BARRIER SYSTEMS

Surface selective epitaxial growth on patterned substrates is used to fabricate quantum dot-tunnel barrier systems, which can be used as sin gle-electron transistor devices. In the centre of a pre-patterned cons triction a self-assembled GaAs quantum dot embedded in barrier materia l is formed during the molecular beam epitaxial growth of an Al0.33Ga0 .67As/GaAs heterostructure. The quantum dot is connected via self-alig ned tunnelling barriers to source and drain electrodes. In-plane-gate electrodes are also realized within the epitaxial growth process. The paper describes the fabrication process of the device and the characte rization of the direct grown quantum dot-tunnel barrier system using s canning-electron microscopy, atomic-force microscopy and transport spe ctroscopy. (C) 1997 Academic Press Limited.