The co-existence of multi-component liquid and solid intermediate phases before the hetero-LPE of III–V solid solutions

1994

Phys. Stat. Sol. (a)

Processes of heterogeneous crystallization of AIIIBV compounds usually differ substantially from homoepitaxial processes. Models describing thermodynamic equilibrium conditions in both three‐ and four‐component homogeneous systems without consideration of the phenomena occurring at the substrate–epilayer interface encounter many limitations. The phase diagrams presented in the literature since long (forming the basis of the selection of technological regimes, in the classical sense), for a wide range of sets require the use of suitable correction of thermodynamic parameters of the systems under consideration. In the present paper a new concept is presented of the physical description of the conditions of thermodynamic quasi‐equilibrium during liquid phase epitaxy of the AxB1–xCyD1–y‐type AIIIBV compounds, assuming pseudomorphic coupling at the substrate–epilayer interface. The relation between the liquidus and solidus curves for the GaxIn1–xPyAs1–y system for its typical heterocomposition is also presented.

Section: Resultsmentioning

confidence: 99%

Section: Theorymentioning

confidence: 99%

A model of internal lattice deformation of the interface during liquid phase heteroepitaxy of AxB1–xCyD1–y-type AIIIBV compounds

1994

Phys. Stat. Sol. (a)

“…The lattice deformation energy causes additional etching of the substrate [1] as the liquid phase and substrate form the isolated system. The separation of the substrate and solution produces the change in the liquidus temperature.…”

Section: Resultsmentioning

confidence: 99%

“…Introduction Crystallographic orientation of the substrate effects the composition of the liquid phase formed by the substrate-source method and also effects the parameters of synthesized layers [1,2]. However, the published data usually describe the crystallization process only and do not provide any information regarding the phenomena appearing during solution formation.…”

mentioning

confidence: 99%

Effect of Surface Orientation of the Substrate on the Saturation State of Solution during Liquid Phase Heteroepitaxy

1992

Acta Phys. Pol. A

Orientation effects during heteroepitaxy appear at the stage of the layer formation and also during the isothermal contact of the multicomponent solution with the binary substrate. In the paper, the analysis of the InP and GaP substrate orientation on the state of liquid phase was carried out. The analysis based on the in situ comparative determination of the contact supersaturation of the Ga-In-P-As and Ga-In-P solutions. It was found that the contact supersaturation of the alloy was connected with the coupling mechanism of the interface with the binary substrate.PACS numbers: 68.55.-a 1. Introduction Crystallographic orientation of the substrate effects the composition of the liquid phase formed by the substrate-source method and also effects the parameters of synthesized layers [1,2]. However, the published data usually describe the crystallization process only and do not provide any information regarding the phenomena appearing during solution formation. It is acknowledged that the contact of the multicomponent liquid solution with the binary substrate leads to the formation of the transition layer. The interphase range introduces therefore a contribution to the energetic balance of the system and it depends mostly on the parameters of the solid phase surface. In the paper, the solubility of binary GaP and InP substrates of various crystallographic orientation in the liquid Ga-In-P and Ga-In-P-As phases during heteroepitaxy was analysed to prove the existence of the orientation effects. The liquid phase was formed either to match the liquid solution equivalent lattice to the substrate lattice or to make them different.The value of the contact solution supersaturation was the criterion applied to estimate the effect of substrate orientation on the condition of liquid phase. The novel design cassette was used in the vertical variant of liquid phase epitaxy and the process was carried by the method [3] enabling to maintain the identical

“…coherent coupling of the region separating the liquid and solid phases [1,3]. Due to this pseudomorphism, a change in the total energy of the system leads to a deviation in the composition of the crystallising solution from the intended one [2].…”

Section: Introductionmentioning

confidence: 99%

Stimulation of Crystalline Lattice Stabilization of Ga-In-P-As Layers during Heteroepitaxy

1995

Acta Phys. Pol. A

Every process of heteroepitaxial synthesis from liquid phase of AIIIBV compounds is based on the contact of saturated solution with the binary substrate. The initial difference in the crystalline lattice parameters or in the radii of mutually substituting atoms of the interface causes the shift of the thermodynamic balance point of the system. The change in the total energy of the system connected with this effect causes the deviation of the actual composition of the crystallising solution with respect to the planed one. In the present paper there are shown the results of the theoretical and experimental analysis of the effect of InP substrates on parameters of the GaxIn1-xPyAs1-y layer crystallised from liquid phase.