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Defects in the GaAs and InGaAs layers grown by low-temperature molecular-beam epitaxy

“…The pit density increases with decrease in temperature from 480 down to 150°С and increase in the arsenic flux (1 < J As / J Ga < 20) [7][8][9], that is, for both cases, with increase in the arsenic concentration in the adsorption layer. At low arsenic fluxes (J As / J III ≤ 0.1), an excess concentration of the III-group elements (Ga, In) occurs on the LT-InGaAs surface, the Ga + In alloy drops of micron sizes are formed from the elements.…”

“…As in the case of GaAs, submicron growth pits are the typical growth-surface elements of InGaAs epitaxial films grown at low temperatures and flux ratios of J As / J III > 1 [9]. The pit density increases with decrease in temperature from 480 down to 150°С and increase in the arsenic flux (1 < J As / J Ga < 20) [7][8][9], that is, for both cases, with increase in the arsenic concentration in the adsorption layer.…”

“…This causes formation of a morphologically non-uniform InGaAs film containing a lot of dislocations. As the arsenic flux increases in the range 0.1< J As /J III <1, the liquid phase is broken to small drops, which is accompanied by a local decrease in the layer growth rate and appearance of typical pits on the surface [9]. The most uniform LT-InGaAs surface without defects is formed at the flux ratios J As / J III = 1-3.…”

“…The lattice mismatch (∆a/a = (a InPa InGaAs )/a InP ) measured for the samples grown at different conditions varies in the interval (3-6)·10 -3 and increases with decreasing temperature and increasing the flux ratio J As /J III [8,9]. The diffraction peak half-width Θ is 24-30 seconds of arc for the samples grown at T g = 480°С and increases up to the value 100 seconds of arc with decreasing temperature and increasing the flux ratio J As /J III .…”

“…In this paper, on the basis of these studies, the problem of defect formation in LT-GaAs and InGaAs is considered. The paper is written using the materials published in [6][7][8][9][10][11][12][13][14][15]. A total review of the current state of the art in the technology of low-temperature molecular beam epitaxy is given in [16].…”