85 research outputs found

    InAsSbBi alloys grown by organometallic vapor-phase epitaxy

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    Journal ArticleProvides information on a study on the growth of InAsSbBi alloys by organometallic vapor-phase epitaxy. Experiment; Results and discussion; Conclusion

    Bandgap control of GaInP using Sb as a surfactant

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    Journal ArticleThe use of surfactants to control specific aspects of the vapor-phase epitaxial growth process is beginning to be studied for both the elemental and III/V semiconductors. To date, most reported surfactant effects for semiconductors relate to the morphology of the growing films. However, semiconductor alloys with CuPt ordering exhibit much more dramatic effects. The change in the CuPt order parameter induced by the surfactant translates into a marked change in the band-gap energy. Previous work concentrated on the effects of the donor tellurium. Te is less than ideal as a surfactant, since the change in band-gap energy is coupled to a large change in the conductivity. This letter presents the results of a study of the effects of an isoelectronic surfactant on the ordering process in GaInP. Sb has been found to act as a surfactant during organometallic vapor-phase epitaxial growth. At an estimated Sb concentration in the solid of 1_x0002_10_x0003_4, order is eliminated, as indicated by the band-gap energy. Surface photoabsorption _x0002_SPA_x0003_ data indicate that the effect is due to a change in the surface reconstruction. Adding Sb leads to attenuation of the peak at 400 nm in the SPA spectrum associated with _x0004_1¯ 10_x0005_ P dimers. The addition of Sb during the growth cycle has been used to produce a heterostructure with a 135 meV band-gap difference between two layers with the same solid composition

    Compositional ordering in semiconductor alloys

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    Journal ArticleCompositional ordering has been observed in a wide variety of III/V semiconductor alloys as well as in SiGe alloys. The thermodynamic driving force is now understood in terms of minimization of the microscopic strain energy of the bonds in the solid. However, the mechanism leading to the specific ordered structures formed is only now beginning to be understood

    Thermodynamic aspects of organometallic VPE

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    Journal ArticleOrganometallic vapor phase epitaxy (OMVPE) is a new crystal growth technique which is rapidly gaining popularity due to its simplicity, flexibility and proven ability to grow excellent quality III/V compounds and alloys for device applications

    Miscibility gaps and spinodal decomposition in III/V quaternary alloys of the type AxByC1−x−yD

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    Journal ArticleThermodynamic concepts have been developed for the calculation of solid-phase miscibility gaps and spinodal decomposition in quaternary alloys of the type AxByC1−x−yD. These concepts have been applied to the analysis of III/V quaternary alloys using the delta-lattice-parameter (DLP) solution model. In addition, the effects of coherency strain energy have been included in the calculation. Results are presented for the systems AlxGayIn1−x−yP, AlxGayIn1−x−yAs, InPxAsySb1−x−y, and GaPxAsySb1−x−y. Even though these systems all have miscibility gaps, they are shown to be stable against spinodal decomposition at all temperatures due to the elastic strain energy inherent in coherent decomposition of single crystalline alloys. Journal of Applied Physics is copyrighted by The American Institute of Physics

    Dual-surfactant effect to enhance p-type doping in III-V semiconductor thin films

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    Journal ArticleSurfactant effects are usually achieved by the addition of a single surface element. We demonstrate by first-principles calculations a dual-surfactant effect of Sb and H on enhancing Zn doping in organometallic vapor phase epitaxially grown GaP thin films. The combined effects of Sb and H lower significantly the doping energy of Zn in GaP, while neither Sb nor H can function alone as an effective surfactant. Our finding suggests a general strategy for enhancing p-type doping of III-V semiconductors by using a metallic-element with H as dual surfactants

    Fundamentals of vapor phase epitaxial growth processes

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    Journal ArticleThe first success with the growth of semiconductor materials by vapor phase epitaxy (VPE) dates back to the 1950's. Today, it is the largest volume technique for the production of both Si and HI/V electronic and photonic devices. Of course, commercial processes for the growth of Si layers, dielectrics, and metals are part of a multi-billion dollar industry. Even for the III/V semiconductors commercial reactors can be purchased yielding 2000 cm2/run, mainly for the production of light emitting diodes and solar cells.The various vapor phase epitaxial processes share a basic underpinning of thermodynamics and kinetics. The vehicle used for this paper will be mainly the organometallic growth of III/V materials. It will briefly discuss key concepts in our understanding of the complex growth process, including both kinetic and thermodynamic aspects of vapor growth. Special attention will be paid to surface processes and the use of surfactants to control the properties of the resulting materials. Our understanding of this topic is still developing rapidly

    Order and surface processes in III-V semiconductor alloys

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    Journal ArticleSemiconductor alloys have become increasingly useful during the last four decades because, through the use of alloys, the properties of semiconductors can be tailored by varying the composition to precisely match the requirements for specific electronic and photonic devices

    Surface photoabsorption transients and ordering in GaInP

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    Journal ArticleHeterostructures and quantum wells can be produced in GaInP without changing the solid composition by simply varying the order parameter. Since CuPt ordering reduces the band-gap energy, changes in the order parameter induced by changes in growth conditions result in heterostructures with band-gap energy discontinuities as large as 160 meV. The most convenient growth parameter to change is the flow rate of the P precursor. However, previous work has shown that under some conditions the change in order parameter is sluggish, giving rise to graded heterostructures. The cause of the slow change in order parameter is the topic of this article. CuPt ordering has been shown to be driven by the formation of _x0004_1 ¯ 10_x0005_ P dimers, characteristic of the (2_x0002_4) surface reconstruction. Thus, this study of the transient in the degree of order induced by changing the flow rate of the P precursor has relied on the use of surface photoabsorption _x0002_SPA_x0003_ to monitor the surface reconstruction during the period after the partial pressure of the P precursor was reduced. The SPA transient has then been correlated with the abruptness of the heterostructure interface, determined from the transmission electron microscopy images and the photoluminescence spectra, for organometallic vapor phase epitaxial _x0002_OMVPE_x0003_ growth at temperatures of 620 and 670 °C using the P precursors phosphine (PH3) and tertiarybutylphosphine _x0002_TBP_x0003_. For TBP at both 620 and 670 °C, the SPA reflectance transient is extremely short, with a time constant of less than 10 s, corresponding to the time response of the OMVPE growth system. Abrupt interfaces are produced using these conditions. For PH3, the SPA reflectance transient is abrupt at 670 °C; however, at 620 °C the SPA response is extremely sluggish, with a time constant of approximately 6.5 min. The effect is tentatively attributed to a surfactant effect due to H on the surface. Corresponding heterostructures were abrupt at 670 °C and graded at 620 °C

    Step structure and ordering in Zn-doped GaInP

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    Journal ArticlePresents the results of a study of Zinc dopant effects on both step structure and ordering in GaInP in an effort to further clarify the disordering mechanism. Comparison of the results obtained for Zinc with those reported for tellurium; Experiment; Results; Discussion; Conclusion
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