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2014 Nous présentons une méthode, combinant l'excitation optique et le remplissage électrique de niveaux profonds, qui permet la mesure de la section de capture des pièges de minoritaires pour les porteurs majoritaires : par exemple 03C3n pour un piège à trous dans un matériau de type n. Cette méthode a été utilisée pour caractériser plusieurs centres profonds dans l'arseniure de gallium. Les résultats suivants ont été établis : le principal piège à électrons « EL 2 » n'est pas un tueur de durée de vie; le coefficient de température de l'énergie d'ionisation de plusieurs niveaux, y compris le niveau du chrome utilisé pour l'obtention des cristaux semi-isolants ; de très grandes (10-15 cm2 ou plus), et de très petites (10-21 cm2) sections de capture pour les électrons pour deux des niveaux étudiés ; des mécanismes de capture envisageables sont mentionnés dans ces demiers cas. Abstract. 2014 A method is presented, which combines optical excitation and electrical refilling of deep levels, allowing one to measure the majority carrier capture cross-section for minority carrier traps : e.g., 03C3n for a hole trap in n-type material. This method has been used to characterize many deep levels in gallium arsenide. The following results are obtained : the main electron trap « EL 2 » is not a hole lifetime killer; the temperature coefficient of the ionization energy for several levels, including the Cr level used for compensation in semi-insulating crystals ; very large (10-15 cm2 or more), and very small (10-21 cm2) electron capture cross-sections for two of the levels ; possible capture mechanisms for these last cases are mentioned.

Zero-net strained multilayer alternating tensile GaInP and compressive InAsP have been grown on (001)InP by metal-organic vapor-phase epitaxy. A structural analysis using transmission electron microscopy (TEM) is reported. A remarkably regular laterally modulated structure has been observed. GaInP- and InAsP-rich vertical zones alternate with a periodicity of 0.28 μm along the lateral [110] direction, thus balancing the mismatch along the [110] rather than the [001] growth direction. TEM experiments suggest that each vertical zone is partially elastically relaxed.

Isochronal and isothermal annealing experiments on defects produced by 1-MeV electron irradiation at room temperature have been performed on n-type GaAs (vapor phase epitaxy layers). In addition to the previously reported irradiation-induced defects E2 to E5, three new traps have been observed (P1 to P3) and their thermal behavior has been studied together with the thermal behavior of the traps E2–E5. The trap E2 is shown to exhibit an annealing kinetics which can be decomposed into the sum of two first-order kinetics, the first one having the same annealing rate as the annealing kinetics of the traps E3 and E5. These observations lead to an interpretation of the annealing mechanism: annihilation of vacancy-interstitial pairs or vacancy-antisite defect pairs, and E2 is tentatively identified as a vacancy.

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Transient-capacitance-spectroscopy experiments yielded electron-emission-rate and electron capture crosssection versus temperature data for the main electron trap in vapor-phase epitaxial Ga&, ln"As layers with 0 & x & 0.21. The ionization energy Ec-ET was obtained from these. Theoretical calculations using the pseudopotential method were performed for substitutional oxygen donor in GaInAs, and the calculated energy levels were compared with the experimental ones. The electron-capture cross sections, as well as optical photoionization data are also discussed from the theoretical point of view. It is argued that most of the experimental evidence is not consistent with the idea that the observed electron trap is simple (substitutional) donor oxygen.