Growth of single-crystal metastable (GaAs)1−x(Si2)x alloys on GaAs and (GaAs)1−x(Si2)x/GaAs strained-layer superlattices

Abstract

Epitaxial zinc blende structure metastable (GaAs)1−x(Si2)x alloys have been grown with 0<x<0.3 on As-stabilized GaAs(100) substrates by a hybrid sputter deposition/evaporation technique. The films, typically 2–3 μm thick, were deposited at 570 °C with growth rates between 0.7 and 1 μm h−1. Alloys with 0<x<0.12 were defect-free as judged by plan-view and cross-sectional transmission electron microscopy (TEM and XTEM) with x-ray diffraction peak widths approximately the same as that of the substrate, 30 arcsec 2θ. XTEM lattice images showed smooth abrupt interfaces. (GaAs)1−x(Si2)x alloys with x>0.12 exhibited increasing evidence of interfacial defects associated with lattice strain when grown on GaAs. However, defect-free alloys with x up to 0.3 were obtained using (GaAs)1−x(Si2)x/GaAs strained-layer superlattice buffer layers to provide a better lattice match.

Supercritical supersaturations and ultrafast cooling of the growth solution in liquid-phase epitaxy of semiconductors

“…Recently, molecular beam epitaxy and metal-organic chemical vapour deposition, where strongly nonequilibrium conditions can be readily created, have been used for this purpose. The wide capabilities of these techniques have been demonstrated in growing GaAs and InP layers on Si, with lattice mismatches of 3.7 and 7%, respectively, and metastable solid solutions (Si 2 ) x GaAs 1−x and (Ge 2 ) x GaAs 1−x [15][16][17][18][19]. However, such grave disadvantages of these methods as high cost and complexity of technological equipment, and poorer luminescence properties of materials grown, make them in some cases inferior to materials grown from solution.…”

Reflection thermal diffuse x-ray scattering for quantitative determination of phonon dispersion relations

“…In particular, novel metastable phases, inaccessible by bulk synthesis techniques, can be produced using kinetically-limited growth processes [14][15][16][17][18][19][20][21] and epitaxial constraints [22][23][24][25][26][27]. Despite the importance of thin films, there are only a restricted number of methods [28,29] for determining phonon dispersion relations for this class of materials.…”