Kinetics of (2x4) -> (3x1(6)) structural changes on GaAs(001) surfaces during the UHV annealing

TL;DR

This study investigates the (2x4) to (3x1(6)) surface reconstruction transition on GaAs(001) during UHV annealing, analyzing the kinetics and intermediate states to improve understanding of epitaxial growth processes.

Contribution

It provides a detailed kinetic analysis of the structural transition on GaAs(001), including activation energies and intermediate disordering states, using RHEED and the JMAK model.

Findings

Transition occurs in two stages with intermediate disorder.

Activation energies and velocities for each stage were determined.

A method for precise surface temperature measurement was proposed.

Abstract

The peculiarities of superstructural transition (2x4) -> (3x1(6)) on the GaAs(001) surface were studied by the RHEED method in the conditions initiated by a sharp change of the arsenic flux. The specular beam intensities RHEED picture dependences on time were obtained during the transition. The measurement results were analyzed within the JMAK (Johnson - Melh - Avrami - Kolmogorov) kinetic model. It was established that the process of structural rearrangement proceeds in two stages and it is realized through the state of intermediate disordering, domains with different reconstructions being coexistent on the surface. The activation energies and phase transition velocities were determined for each of the stages. The procedure for precise determination of GaAs(001) surface temperature using the features of the a(2x4)->DO transition process kinetic was proposed. The results of this work allow us to broaden our understanding of the reconstruction transitions mechanisms. This information has a key (fundamental and applied) nature for the technologies of epitaxial growth of multilayer heterostructures, where the interface planarity and the sharpness of composition profile are of particular importance.