X-ray diffraction and channeling-Rutherford backscattering spectrometry studies of ion implantation damage in AlxGa1−xAs

Abstract

X-ray diffraction and channeling-Rutherford backscattering spectrometry (RBS) were employed to investigate damage accumulation in AlxGa1−xAs (x=0.50, 0.75, 0.85, and 1.0) irradiated at 80 K with MeV ions. The x-ray measurements, performed both before and after warming the samples, showed a transition in the strain accumulation behavior as the Al content increased. For samples with low Al content, x=0.50, the strain increased monotonically with fluence until the sample amorphized, a behavior similar to GaAs. For samples with x⩾0.75, the strain initially increased, then plateaued, and finally diminished at high fluences. The RBS data, obtained at both 80 K and room temperature, revealed a similar dependence of the amorphization behavior upon Al content. For pure AlAs films, amorphization in the bulk was not observed even after a fluence of 2×1017 cm2 of 1.7 MeV Ar+. For films with low Al content, however, the AlxGa1−xAs layer readily amorphized with a fluence of only 6.8×1014 cm2 of 1.7 MeV Ar+. From these data, along with previously published information provided by transmission electron microscopy studies, a model for damage accumulation in ion irradiated AlxGa1−xAs is proposed.

Neon and Manganese Ion Implantation into AlInN

“…After annealing at 750 o C, the strain increases with dose until it reaches a short plateau and then decreases with further increase in dose. Similar dose dependent behavior of the strain variation has been reported by Partyka et al for the argon implanted AlGaAs/GaAs [51].…”

Atomic-level heterogeneity and defect dynamics in concentrated solid-solution alloys

“…Due to their importance in optoelectronics, radiation damage in III -V semiconductors have been studied extensively [80][81][82][83][84]. The case of Al x Ga 1-x As compounds is particularly intriguing, in that it shows a drastic change in damaging behavior when only a small fraction of Al is used to replace Ga. [85]. This is particularly surprising since during the addition of Al, the crystal structure remains the same, and there are no drastic changes in lattice constant, band gap or any other basic materials property.…”

Lattice strain in irradiated materials unveils a prevalent defect evolution mechanism

“…Since the early 1980's, research works dealing with the study, by XRD, of the strain induced by ion (or even neutron and electron) energy deposition have covered a wide range of materials, including mainly semiconductors 24,[28][29][30][31][32] and insulators 16,[33][34][35][36] but also, though more recently, metals 15,[37][38][39] . In all these works, two steps in the development of strain are observed.…”

“…On the other hand, in materials that retain their original crystalline structure, the microstructure is nonetheless also severely affected, and two situations, that at first might seem conflicting, are observed as far as the strain evolution is concerned. In the first situation, a strain saturation phenomenon is noticed at high ion fluence (number of ions per unit surface) [30][31][32] , and it is ascribed to a balance between the strain induced by interstitial and vacancy defects 30 or to the trapping of point defects at stacking faults 31 . However, it is worth mentioning that in most cases, the difficulty of analysing the complex XRD data at high ion fluence is likely one of the reasons why a saturation was assumed.…”