Quantum dot structures: Fabrication technology and control of parameters

Abstract

Quantum dot (QD) semiconductor heterostructures for device applications are currently synthesized using the effect of spontaneous transformation of the growth surface at the initial stage of heteroepitaxy of lattice-mismatched layers. When a certain critical layer thickness is reached, the planar growth surface is transformed into an array of nanoscale islands, as was first demonstrated for an InAs/GaAs system. For various device applications, it is desirable to control the shape and size of individual QDs. This is achieved by variation of the effective thickness of the deposited InAs layer, deposition of several QD layers, the use of various matrix materials and a metamorphic buffer layer, and the addition of a small amount of nitrogen into QDs and the matrix material.