Epitaxial layers of In0.53Ga0.47As lattice matched to InP substrates have been grown by molecular beam epitaxy. The (100) InP substrate surfaces were first oxide passivated and then thermally cleaned under 1.5×10−6 Torr of arsenic moleuclar beam exposure (i.e., 1.24×1014 As4/cm2 sec). When they were heated to 500 °C, damage-free surfaces without oxygen and carbon contamination were obtained. The surface chemical composition as a function of the thermal cleaning temperature was studied with Auger electron spectroscopy. In0.53Ga0.47As epilayers of highly uniform composition were grown over a 7-cm2 InP substrate using an In/Ga coaxial oven design. Reproducible In and Ga beam fluxes to obtain lattice-match condition were achieved by adjusting the aperture ratio of the In and Ga reservoirs, and the oven temperature. Net electron concentration as low as 3×1015 cm−3 has been achieved for the In0.53Ga0.47As layers.

A photoluminescence study of C, Si, Ge, Be, Mg, and Zn acceptors in AlxGa1−xAs is made. The binding energy of these acceptors is determined from the free-to-bound transitions at 75 K as a function of aluminum composition up to x∼0.4. It is observed that C, Be, and Mg behave like effective mass acceptors in AlxGa1−xAs while Si, Zn, and Ge show positive deviations from the effective mass theory with Ge exhibiting the maximum deviation. This difference in the behavior of the acceptors is suggested to be due to the difference in their central cell corrections in GaAs. The relative merits of these acceptors, in terms of their solubility, ionization energy, and diffusivity are considered. It is concluded that Mg is an attractive acceptor dopant in AlxGa1−xAs grown by liquid phase epitaxy.

Results of photoluminescence and Hall effect measurements of p-type Ge-doped Ga0.60Al0.40As grown by liquid phase epitaxy are reported. The effective segregation coefficient for Ge for growth at 785 °C is estimated to be ∼2×10−3. The photoluminescence spectra at 5.5 K are characterized by two edge emission bands at ∼1.91 and ∼1.88 eV and a broadband at ∼1.55 eV. The edge emission bands are identified to be donor-acceptor pair recombination bands involving the same donor but two different acceptors. The ionization energy of the donor is estimated to be 50–60 meV and the acceptor ionization energies are estimated to be ∼60 and ∼100 meV for the 1.91- and 1.88-eV bands, respectively. The deep acceptor is believed to involve a background impurity, most likely C or Si. It is suggested that the 1.55-eV band arises from a next-nearest neighbor complex consisting of Ge on an arsenic site and an As vacancy. Post-growth annealing treatment at 830 °C is found to decrease the photoluminescence intensity suggesting the presence of annealing induced nonradiative centers.

The temperature dependence (from 6 to 300 K) of the near band gap photoluminescence (PL) of n-type InGaAsP is investigated. These layers, epitaxially grown on InP substrates, span the entire range of lattice matched compositions of the quaternary alloy. The spectral width of the PL emission and its temperature dependence are found not to vary with composition. However, compositional grading, especially evident at the center of the InGaAsP alloy range, often results in significant linewidth increase. These results are correlated with double crystal x-ray diffraction measurements. The experimental results are compared with predictions of van Roosbroeck–Shockley formalism.

Measurements of the radius of curvature of GaAs substrates metallized with Ti-Pt bilayer thin films and annealed at 450 ·C indicate that the state of stress of the substrate (tension versus compression) at the interface varies with the thickness ratio of the metals. Increasing thicknesses ofTi (Pt) result in increasing tensile (compressive) stresses in the substrate. An appropriate choice of the thickness ratio ofTi/Pt yields an unstressed substrate after annealing. It was found in most cases that extensive plastic deformation occurred in the film during annealing.PACS numbers: 68.60. + q, 68.25. + j, 81.40. -z J.