Regularities of ion-beam-induced crystallization and properties of InAs-QD/GaAs(001) semiconductor nanoheterostructures

Abstract

A novel method of the ion-beam-induced crystallization of quantum-size semiconductor eterostructures has been proposed. Using atomic force (AFM) and transmission electron microscopy (TEM), the capacitance–voltage (C–V) method, and photoluminescence (PL) measurements, we have studied the main regularities of ion-beam-induced crystallization and the properties of InAs quantum dots (QDs) on GaAs single crystal substrates with (001) crystallographic orientation as functions of temperature, ion current, and ion energies. It is shown that, in order to grow InAs hut structures, the optimal temperature range is from 500 to 550°C. An intense development of dome clusters is observed at higher temperatures. It is found that an increase in the ion current in an interval from 60 to 120 μA at a temperature of 500°C and an ion energy of 150 eV inconsiderably affects the average sizes of nanoislands. It is shown that, in an ion energy range from 150 to 200 eV and at a constant temperature of the process of 500°C and bam current of 120 μA, bands of stability of medium sizes (∼15 nm) and surface density (∼10¹¹ cm^–2) are observed.