Effect of surface tension on the growth mode of highly strained InGaAs on GaAs(100)

Abstract

We have investigated the molecular beam epitaxy growth of highly strained InGaAs on GaAs(100) as a function of the anion to cation flux ratio. Using reflection high energy electron diffraction the evolution of the film morphology is monitored and the surface lattice constant is measured. It is found that the cation to anion flux ratio dramatically affects the growth mode. Under arsenic-rich conditions, growth is characterized by a two-dimensional (2D) to three-dimensional (3D) morphological transformation. However, for cation-stabilized conditions, 3D islanding is completely suppressed, and 2D planar growth is observed. We associate these differences in the growth mode with corresponding changes in the surface tension of the overlayer. A high surface tension stabilizes 2D growth. An analysis which relates surface tension to a critical thickness for the onset of coherent island formation supports this view.

Quantum coherence in semiconductor nanostructures for improved lasers and detectors.

“…Previous studies have identified that group III stabilized surfaces are stable against island formation while arsenic stabilized surfaces are not [24]. These results do not contradict previous observations, but suggest that extremely arsenic enriched heterostructure surfaces found in the MOVPE environment can be stable against islanding, in contrast to the less arsenic rich MBE surfaces that almost categorically form QD for In 0.4 Ga 0.6 As deposition on GaAs.…”

Stress and surface energies versus surface nanostructuring: the InGaAs/InP(001) epitaxial system

“…In that case a layer-by-layer growth mode was preserved. Such a behaviour was found for InAs/InGaAs [16,17], (In,Ga)As/GaAs [18], and In(Ga)As/ InP(0 0 1) [19]. The latter epitaxial system is particularly interesting because one can investigate the effects of both strain elastic energy and surface energy.…”

“…Up to 7 InAs ML (respectively 10 In 0.82 Ga 0.18 As ML) were grown in the layer by layer mode, when the 2D-3D transition occurred between 2 and 3 InAs ML (respectively 4 and 5 In 0.82 Ga 0. 18 while the surface roughening process occurs in both cases from the very beginning at arsenic saturated growing.…”

In situ control of strain-induced dot structure by arsenic/phosphorus replacement

“…This is because the surface is not completely arsenic-stabilized under the small pulses of AsH 3 and the release of strain by forming the dots was partly suppressed. 15,16 Unlike in conventional dot formation by the self-organization mechanism, where dot formation is completed in less than one minute, there is enough time in this step-bystep reformation of dots to insert a molecular beam in order to put dopants into the dots or to produce a composition gradient in the dots. To create a composition gradient in the dots as our first attempt, we examined the possibility of adding gallium or indium during dot reformation, and investigated changes induced.…”