Calculation of the pseudobinary alloy semiconductor phase diagrams

Abstract

To calculate the pseudobinary alloy semiconductor phase diagrams the quasiregular solution theory is used. The interaction parameter in the solid (Q) is determined on the base of an analysis of the X-ray diffuse scattering and the composition dependence of the elastic constants. The values of liquid interaction parameter in the pseudobinary solutions Gap-InP, GaAs-InAs, GaAs-AIAs, GaAs-Gap, and GaAs-GaSb are determined by coincidence between calculated curves and experimental points on the liquidus or solidus lines. The R values are also used for the calculation of the insolubility curves in the solid phase. Zur Berechnung der Phasendiagramme von pseudobinaren Legierungshalbleitern wird dieTheorie quasiregularer Losungen benutzt. Der Wechselwirkungsparameter im Festkorper (a) wird aus der Analyse der diffusen Rontgenstreuung und der Abhangigkeit der elastischen Konstanten von der Zusammensetzung bestimmt. Die Werte der Flussigkeitswechselwirkungsparameter in den pseudobingren Losungen yon Gap-InP, GaAs-InAs, GaAs-AlAs, GaAs-GaP und GaAs-GaSb werden aus der Koinzidenz zwischen berechneten Kurven und experimentellen Punkten auf der Liquidus-oder Soliduskurve bestimmt. Die R-Werte werden auch fur die Berechnung der Nichtloslichkeitskurven in der festen Phase benutzt.

Growth of homogeneous semiconductor mixed crystals by the traveling liquidus-zone method

“…7. The Si-Ge phase diagram [16] is similar to the InAs-GaAs pseudobinary phase diagram [17] and homogeneously mixed crystals of Si 1 À x Ge x are easily grown [10,11] similarly to In 1 À x Ga x As. In the growth of Si 1 À x Ge x , low melting point Ge is used as a zone former.…”

Correlation between thermodynamic instability of AIIIBv heterocompositions and degradation of devices based on these materials

“…I n [8] in designing the phase diagrams the boundaryinduced energy effects were disregarded. Therefore, the nature of processes in composition-modulated AIIIBV heterocompositions can be significantly different from the processes predicted by the model of [8]:…”

“…In heterocomposition formation the compositions of interfacial layers are significantly different from those that can coexist according to the phase diagrams [8]. If, however, no environmental factors accelerate the diffusion, the heterocomposition degradation is negligible because of the weak diffusion processes in AIIIBV materials I n operating the devices two alternative mass transfer intensification mechanisms can be proposed.…”

Thermodynamic instability of ultrathin semiconductor superlattices: The (001) (GaAs)1(AlAs)1structure

“…For GaAlAs2 we found AZschem 5^ +14.9 meV, similar to the chemical energy 0.4 kcal/mole = +17.3 meV measured for a disordered G f d x A\\x As alloy at x = y by diffuse x-ray scattering. 26 Even simulating the small experimental lattice mismatch Aa by setting AE ms -0, we still predict 27 AH°>0.…”