Characterization of InGaP/GaAs heterointerfaces grown by metal organic vapour phase epitaxy

In GaAs/InGaP/GaAs structures grown by metal organic vapor-phase epitaxy (M OVPE), the two heterointerfaces are not identical. Normal photoluminescence (PL) features corresponding to the band gaps of GaAs and InGaP are seen fo r InGaP layer grown on GaAs, However, an intense long-wavelength feature is observed if we grow GaAs on InGaP (inverted structure) while the features of InGaP and GaAs are suppressed. The nature of interfacial regions is inve stigated by using different gas switching sequences, which can influence th e interfacial region composition. Significantly, we find anomalous PL featu res similar to those observed in the case of inverted structure if we brief ly interrupt the growth of InGaP on GaAs and introduce AsH3 during the grow th interruption. Secondary-ion mass spectrometry (SIMS) measurements and pr eliminary results of the compositional analysis of the interfacial layers b ased on high resolution X-ray diffraction (HRXRD) and PL measurements sugge st that a deleterious effect arises with the exposure of InGaP surface to A sH3 and is attributed to the formation of an interfacial InGaAsP layer, (C) 2000 Elsevier Science B.V. All rights reserved.