Analysis of defect structure in silicon. Characterization of samples from UCP ingot 5848-13C

Statistically significant quantitative structural imperfection measurements were made on samples from ubiquitous crystalline process (UCP) Ingot 5848 - 13 C. Important trends were noticed between the measured data, cell efficiency, and diffusion length. Grain boundary substructure appears to have an important effect on the conversion efficiency of solar cells from Semix material. Quantitative microscopy measurements give statistically significant information compared to other microanalytical techniques. A surface preparation technique to obtain proper contrast of structural defects suitable for QTM analysis was perfected

InAsSbBi alloys grown by organometallic vapor-phase epitaxy

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

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

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

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

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

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

Thermodynamic aspects of organometallic VPE

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

Order and surface processes in III-V semiconductor alloys

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

Fundamentals of vapor phase epitaxial growth processes

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

Nonequilibrium composition profiles of alloy quantum dots and their correlation with the growth mode

Journal ArticleEquilibrium composition profiles (CPs) of epitaxial alloy quantum dots (QDs) are well established theoretically. However nonequilibrium CPs may occur experimentally. Using an atomistic-strain-model Monte Carlo simulation method, we demonstrate a striking correlation between the nonequilibrium CPs of QDs and the kinetic growth mode: the layer-by-layer growth (LG) and faceted growth (FG) form a coreshell structure having the triangle core of the unstrained and V-shaped core of the strained component, respectively, and both are distinctly different from the equilibrium CP. Comparing simulations with experiments, we infer that the InGaAs dots on GaAs grow by FG, while GeSi dots on Si grow first by LG followed by FG. Our findings suggest a possible method for controlling the CPs of QDs by selecting the growth mode