A New Approach to Grow High Quality Bulk lnxGa1-xAs Crystal by Multi-component Zone Melting Method

Abstract

An analytical study has been carried out to grow high-quality bulk InGaAs crystals by the two-step multi-component zone melting (MCZM) method. Characterization of bulk InGaAs crystal grown by the two-step MCZM method has confirmed the existence of large amount of strain of the order of 10 in bulk InGaAs crystal due to approximately exponential variation of composition from 0.06 to 0.29 in the first step growth process of the two-step MCZM technique. From the experimental evidence, it has been confirmed that the composition-dependent strain is associated with the breakage issue in the MCZM grown crystals. Using an axially symmetrical strain model, the quantitative amount of strains and their distributions have been studied for various compositional profiles including the currently used profile. In addition, the spatial variations of strain components for various compositional profiles have been analyzed using the twodimensional strain maps. The strain values and their distributions corresponding to the various compositional profiles have been compared and a suitable compositional profile has been proposed to grow compositionally homogeneous high quality bulk InGaAs crystals using the MCZM method. Further, from the dependency of the strain values with the crystal length and diameter, the possibility of the growth of large-size crystals has been investigated. It has also been studied that the proposed compositional profile allows achieving the growth parameters easily for the two-step MCZM growth process.