GaInAs/InP selective area metalorganic vapor phase epitaxy for one-step-grown buried low-dimensional structures

Abstract

The selective area epitaxy of GaInAs/InP layers grown by low-pressure metalorganic vapor phase epitaxy through SiO2 patterned masks was investigated. The layers are found to develop mesa structures limited by {111} and (100) facets outside of the opened mask, and perfect selective epitaxy is obtained. The absence of GaInAs growth on {111} facets allows the fabrication of very narrow buried GaInAs layers in a single growth step. For both materials, the growth rates are found to depend strongly on the mask geometry owing to surface diffusion of the reactant species from the no- or low-growth SiO2 mask and {111} facets toward (100) surfaces. A detailed quantitative analysis is made to identify the critical parameters that control the growth behavior, and a model is described from which the upper limit of the growth rates for any mask design can be calculated. Low-temperature cathodoluminescence measurements show strong emission of the buried GaxIn1−xAs layers and indicate local stoichiometry variations Δx≂±5% around the x=47% lattice-matched composition that are attributed to different diffusion coefficients of the reactant species on the SiO2 mask and {111} facets. The results show that selective area metalorganic vapor phase epitaxy is a promising technique for the fabrication of one-step-grown buried quantum-well wire arrays and narrow cavity InP-based buried lasers.