Metalorganic Vapor Phase Epitaxial Growth Parameter Dependence of Phase Separation in Miscibility Gap of InGaAsP

Abstract

The generation mechanism of the immiscibility of InGaAsP grown by metalorganic vapor phase epitaxy (MOVPE) is investigated. The growth condition dependence of the immiscibility is examined in detail using particular photoluminescence (PL) characteristics observed in the boundary composition between stable and unstable compositional regions. A lower growth rate or a larger V/III ratio is effective for suppressing phase separation. To explain this growth condition dependence, some factors related to surface energy should be taken into consideration.

Coexistence properties of phase separation and CuPt-ordering in InGaAsP grown on GaAs substrates by organometallic vapor phase epitaxy

“…These results revealed that the degree of the CuPt-ordering in InGaAsP with a low arsenic content was significantly enhanced in the 630 1C-grown sample. The results for CuPt-ordering in the TED patterns are consistent with those in the photoluminescence measurements reported previously [14][15][16][17].…”

“…The suppression of the phase separation was quantitatively understood by the formation of the CuPt-ordering in InGaAsP [15]. The CuPt-ordering is easily formed on the reconstructed surface, but at higher temperatures the adatom diffusion along the surface disrupts the surface reconstruction and therefore suppresses the CuPt-ordering [16]. Therefore, there is a competitive relationship between the CuPt-ordering and the phase separation via the surface reconstructions.…”

“…We have focused on the generation mechanism of immiscibility in OMVPE grown InGaAsP on GaAs substrates and performed systematic studies [14][15][16][17]. In previous studies, we have reported on the suppression of the phase separation in the OMVPE grown InGaAsP with low arsenic contents and attributed the suppression to the surface reconstructions such as P(2 Â 4), which is the origin of CuPt-ordering [15].…”

Distributed Bragg reflector lasers emitting between 696 and 712 nm

“…Whereas for wavelengths below 690 nm strained ternary InGaP quantum wells (QWs) can be employed as active regions, the wavelength range between 690 and 720 nm can be better addressed with tensile-or compressive-strained QWs consisting of quaternary InGaAsP [7][8][9]. Growth of compressively strained InGaAsP layers by metalorganic vapour phase epitaxy (MOVPE) is known to be challenging due to the occurrence of phase separation [10][11][12]. This tendency is strongest for mid-range compositions and lower growth temperatures and is usually referred to as the miscibility gap [10].…”

“…Growth of compressively strained InGaAsP layers by metalorganic vapour phase epitaxy (MOVPE) is known to be challenging due to the occurrence of phase separation [10][11][12]. This tendency is strongest for mid-range compositions and lower growth temperatures and is usually referred to as the miscibility gap [10]. Therefore, the growth conditions have to be carefully selected to obtain randomly alloyed InGaAsP QWs.…”