The morphology of ordered structures in III–V alloys: inferences from a TEM study

We examine CuPt-B atomic sublattice ordering in Ga In P 0.51 0.49 (GaInP) and Ga In As 0.47 0.53 (GaInAs) III-V alloy films grown by atmospheric-and low-pressure metalorganic chemical vapor deposition on singular and vicinal (001) substrates. The influences of growth conditions and substrate miscut on double-and single-variant ordered microstructures are investigated using transmission electron microscopy (TEM). Relatively thick (>1-2Êmm) double-variant ordered GaInP and GaInAs films show complementary superdomain formation. Single-variant ordered films on <111>B-miscut substrates contain single-phase domains, separated by antiphase boundaries (APBs). The appearance of APBs in TEM dark-field images is anticipated from electron diffraction theory. INTRODUCTIONCuPt-B atomic ordering occurs in several epitaxial III-V alloys grown under appropriate conditions. Ga In P 0.51 0.49 (GaInP) on GaAs and Ga In As

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“…Ordered GaInP microstructural details were reported by Baxter et al [10]. Symmetric double-variant ordering occurs on 0¡ GaAs.…”

Section: Gainpmentioning

confidence: 79%

CuPt-B Ordered Microstructures in GaInP and GaInAs Films

et al. 1999

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“…17 Figure 1 shows two typical high-resolution cross-section TEM pictures of ordered GaInP. 10 These two pictures are representative for areas that have a well-defined phase for each ordered variant 5 Figure 1(a) is from a small selected area of sample K518-0°. A 'zigzag' stacking sequence of two ordered variants is clearly shown.…”

Section: Methodsmentioning

confidence: 99%

“…3 For an extended period of time, the ordered structure grown on the exact (001) substrate or [111] A tilted substrate with two [111] B ordered variants co-existing has been treated as equivalent to a singlevariant ordered structure but with poor quality, although quasi-periodically stacked micro-domain twins along the growth direction [001] had been observed and analyzed for double-variant ordered GaInP alloys in structural studies. 4,5 The implication for the existence of such a quasi-periodic structure has recently been discussed theoretically in terms of a new type of superlattice termed an orientational Ł Correspondence to: A. Mascarenhas superlattice (OSL) 6 -8 or anti-phase boundary superlattice.…”

Section: Introductionmentioning

confidence: 99%

“…6,7 For the doublevariant ordered GaInP alloy that resembles an OSL, the structure has periodically stacked micro-ordered-domain twins with a typical period of ¾40Å. 4,5 An increase in the bandgap is expected with respect to the pure CuPt ordered structure for an OSL that has the same order parameter Á for the constituent layers. 6 -9 In addition to the band structure modification, the change in the crystal symmetry is expected to result in changes in the selection rules for optical transitions.…”

Section: Introductionmentioning

confidence: 99%

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Effects of the orientational superlattice on the electronic and vibrational properties of CuPt ordered GaInP alloys

Zhang

Mascarenhas

2001

J Raman Spectroscopy

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“…However, there are many experimental indications of ordering effects in III/V epilayers [1]. Long-range ordering in III-V ternary alloy semiconductors deserves careful investigation since it is related with significant changes in the electrical and optical properties and provides an additional degree of freedom in band engineering.…”

Section: -Introductionmentioning

confidence: 99%

X-ray diffraction study on the correlation between ordered domains size and ordering degree in InGaP/GaAs alloy layers

Francesio¹,

Alagna²,

Capelle³

et al. 1997

Nouv Cim D

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Summary. --Undoped heteroepitaxial layers of InGaP with constant-thickness grown tattice matched on GaAs substrates with miscut angles of 0 o, 2 o, 6 ~ with respect to the (001) plane and n-and p-doped samples grown on 2 ~ off substrates have been studied by X-ray diffraction. The examined InGaP layers spontaneously order in CuPt-like domains presenting (-1, 1, 1) and (1, -1, 1) variants. The doubling of periodicity has been revealed by the appearance of extra refiections normally forbidden. The full width at half maximum and the integrated intensity of these reflections were measured in order to investigate the degree of order within the domains and the results have been discussed on the basis of the correlation between domains size and ordering degree. Finally, the doping level effects (Si [n]

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The morphology of ordered structures in III–V alloys: inferences from a TEM study

Cited by 98 publications

References 9 publications

CuPt-B Ordered Microstructures in GaInP and GaInAs Films

CuPt-B Ordered Microstructures in GaInP and GaInAs Films

Effects of the orientational superlattice on the electronic and vibrational properties of CuPt ordered GaInP alloys

X-ray diffraction study on the correlation between ordered domains size and ordering degree in InGaP/GaAs alloy layers

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