Effect of growth conditions on epitaxial lateral overgrowth of InP on InP/Si (001) substrate by hydride vapor phase epitaxy

Abstract

Epitaxial lateral overgrowth of (ELO) InP on (001) InP/Si substrate is explored in a low pressure hydride vapor phase epitaxy system under various growth conditions. The effect of gas phase supersaturation on boundary plane formation of ELO and the behavior of dislocations in the grown layers are investigated. We found that the growth rate on (1 1 1)A boundary plane is determined by Burton-Cabrera-Frank model, which predicts a parabolic relationship between gas phase supersaturation and growth rate. Formation of (1 1 1)A plane will cause stacking faults in the grown InP layer. They will interact and annihilate each other and introduce fresh dislocations during the growth. Gas phase supersaturation can also be changed by varying opening separation distance. Low gas phase supersaturation is obtained by decreasing the distance between two openings. It gives rise to a lower staking fault density due to the suppression of nucleation of { 1 1 1 } facet plane at the edge of ELO. Etch pit density (EPD) and X-ray diffraction (XRD) techniques are used to estimate the dislocation density. Full width at half maximum of rocking curve at (004), (115) and (117) reflections were used to calculate the dislocation density in ELO InPISi. Experimentally measured etch pit density is smaller than the dislocation density derived from XRD data. In general the dislocation density is dependent on gas phase supersaturation. In this work, we demonstrate that it is possible to grow high quality InP layer on silicon substrate by epitaxial lateral overgrowth technique under optimized growth conditions.