Controlled ordering and positioning of InAs self-assembled quantum dots

Lee, H.; Johnson, J. A.; Speck, J. S.; Petroff, P. M.

doi:10.1116/1.1306281

Cited by 85 publications

(57 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been proposed that dot ordering is driven by the elastic field of the subsurface stressors. Usually, these subsurface stressors are buried dots themselves [14,15]; however, they can take the form of subsurface dislocation arrays [16] or buried strained layers on patterned substrates [7,17]. Subsurface stressors lead to a modulation in the stress field and associated strain field on the growth surface, which impacts both adatom diffusion and island nucleation rates [15,18].…”

Section: Introductionmentioning

confidence: 99%

Elastic fields and energies of coherent surface islands

Jónsdóttir

Halldorsson

Beltz

et al. 2006

Modelling Simul. Mater. Sci. Eng.

View full text Add to dashboard Cite

We present simple models based on isotropic elasticity for determining the stress fields in the vicinity of, and the elastic energy associated with, coherent surface islands (i.e. a quantum dot or a nanorod). The first method treats the surface island as an areal point of dilatation and does not account for details of the island shape. Next, the finite element method is used to study simple island shapes such as spherical caps and cylinders, with a particular focus on the island aspect ratio. The latter is used in conjunction with the analytic results to develop empirical expressions for stress field and energy as functions of aspect ratio, which are somewhat insensitive to other features of the geometry. The analyses are used to assess the effect of lattice mismatch, dot volume and dot/surface contact area on the induced stresses and elastic energies. Furthermore, the interaction energy between surface islands is determined by finite element analyses. Outputs from these analyses are then used in an optimization of several cases of ordering of islands. The results show that for a range of idealized geometries, the shape of the surface island has little impact on the strain energy, and thereby the interaction energy.

show abstract

Section: Introductionmentioning

confidence: 99%

Elastic fields and energies of coherent surface islands

Jónsdóttir

Halldorsson

Beltz

et al. 2006

Modelling Simul. Mater. Sci. Eng.

View full text Add to dashboard Cite

show abstract

“…To achieve this goal, many groups have investigated the formation of QD arrays using multilayer high stepped vicinal substrates or strained layer growth on patterned substrates. [6][7][8][9][10] These approaches, however, often suffer from a degradation of the structural perfection and optical quality of the QD arrays, which is attributed to step edge roughness or pattern irregularities on the dot-diameter and dot-to-dot distance length scales, introducing defects and size fluctuations in the QD arrays.…”

mentioning

confidence: 99%

Formation of InAs quantum dot arrays on GaAs (100) by self-organized anisotropic strain engineering of a (In,Ga)As superlattice template

Mano

Nötzel

Hamhuis

et al. 2002

Applied Physics Letters

View full text Add to dashboard Cite

We demonstrate the formation of well-defined InAs quantum dot (QD) arrays by self-organized engineering of anisotropic strain in a (In,Ga)As/GaAs superlattice (SL). Due to the accumulation and improvement of the uniformity of the strain-field modulation along [011], formation of InAs QD arrays along [0-11] with 140 nm lateral periodicity is clearly observed on the SL template when the number of SL periods is larger than ten. By enhancing the In adatom surface migration length at low growth rates, clear arrays of single InAs QDs are obtained. The QD arrays exhibit strong photoluminescence efficiency that is not reduced compared to that from InAs QD layers on GaAs. Hence, ordering by self-organized anisotropic strain engineering maintains the high structural quality of InAs QDs.

show abstract

“…Consequently, some years ago a templated selfassembly of semiconductor nanostructures was introduced, [30][31][32][33][34][35][36][37] combining growth on patterned substrates for the definition of an initial two-dimensionally periodic island layer with subsequent vertical ordering due to the strain fields of the buried quantum dots in a multidot layer system. 38,39 So far, in particular, three-dimensionally ordered structures of InAs/GaAs ͑Ref.…”

Section: Introductionmentioning

confidence: 99%

X-ray diffraction investigation of a three-dimensional Si/SiGe quantum dot crystal

et al. 2009

View full text Add to dashboard Cite

High-resolution x-ray diffraction was employed to study the structural properties of a three-dimensional periodic arrangement of SiGe quantum dots in a Si matrix. Using extreme ultraviolet lithography at a synchrotron source a two-dimensional array of pits ͑period 90ϫ 100 nm 2 ͒ was defined and transferred into a ͑001͒ Si wafer by reactive ion etching. By molecular-beam epitaxy SiGe islands of about 30 nm diameter and 3 nm height were grown into the pits. Subsequent deposition of Si spacer layers of 10 nm thickness and SiGe island layers results in a three-dimensionally periodic arrangement of quantum dots, mediated by the strain fields of the buried dots. Their so far unmatched structural perfection is assessed by coplanar x-ray diffractometry using synchrotron radiation. Reciprocal-space maps around the ͑004͒ and ͑224͒ reciprocal-lattice maps were recorded and analyzed to get quantitative information on the disorder of the dot positions and to obtain the mean Ge content of the dots. In addition, information on the strain fields was deduced from the analysis of the diffraction data. Together with atomic force microscopy data on the island shape and size distribution, a complete structural characterization is achieved.

show abstract

Controlled ordering and positioning of InAs self-assembled quantum dots

Cited by 85 publications

References 26 publications

Elastic fields and energies of coherent surface islands

Elastic fields and energies of coherent surface islands

Formation of InAs quantum dot arrays on GaAs (100) by self-organized anisotropic strain engineering of a (In,Ga)As superlattice template

X-ray diffraction investigation of a three-dimensional Si/SiGe quantum dot crystal

Contact Info

Product

Resources

About