The Characterization of Liquid Phase Epitaxial Indium-Gallium - Arsenide - Phosphide and Indium-Gallium - Arsenide

91 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1981.The growth of InGaAsP and InGaAs by liquid phase epitaxy (LPE) on InP substrates has been investigated to obtain the optimum crystal growth parameters to produce high quality epitaxial layers. The lattice mismatch of these layers with respect to the underlying InP substrate was determined by X-ray diffraction, and the energy gap was obtained by optical spectrophotometer transmission measurements. The distribution coefficients for the growth of lattice matched InGaAsP in the 1.15 to 1.31 (mu)m spectral region were determined. The surface morphology of the epitaxial layers was found to be more sensitive to lattice mismatch for the longer wavelength material ((lamda)(,g) > 1.21 (mu)m). A detailed study of the influence of the melt composition on the composition of the resultant epitaxial layers was conducted for (lamda)(,g) = 1.15 (mu)m InGaAsP. The effect of the growth temperature on the solid composition of the layers was determined. Constant composition layers are produced by growth at a constant temperature, while growth techniques involving a cooling rate produce compositionally graded material. The addition of dopants to the melt was shown to influence both the lattice mismatch and energy gap. Auger profiling was used to study the effect of lattice mismatch on the chemical interface abruptness of InGaAsP/InP heterojunctions and the effect of dissolution on the interface of InGaAs/InGaAsP heterojunctions.The minority carrier diffusion lengths of LPE InGaAsP and InGaAs and VPE InP were obtained from photocurrent measurements using the scanned laser spot technique on beveled p-n junctions. The influence of lattice mismatch on the hole diffusion length in LPE InGaAsP ((lamda)(,g) = 1.15 (mu)m) was studied and it was found that the longest diffusion length was obtained when the layer is lattice matched to the InP substrate. Electron diffusion lengths were determined over a wide range of hole concentrations in LPE InGaAsP and InGaAs layers grown from melts doped with Zn. The electron diffusion lengths were longest at the lowest hole concentrations and decreased monotonically as the concentration increased. The hole diffusion length in n-type InP grown by the hydride VPE process was studied as a function of the In boat source temperature. The diffusion length was found to increase with increasing source temperature.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD