Bulk growth of polycrystalline indium phosphide

The growth of polycrystalline indium phosphide of different grain sizes varying from 15μm to 4000μm has been discussed. The materials have been characterized by a variety of methods including electrical and optical techniques. Device application of the InP prepared was demonstrated by the fabrication of Ag Schottky diodes andp ⁺-n junction using Zn diffusion. The variation of mobility with varying grain size has been determined experimentally and the results interpreted taking into account the effect of compensation.     

Initial growth behaviour of indium phosphide on molybdenum substrates

We describe the initial stages of indium phosphide growth on preferentially etched molybdenum using an In-PCl₃-H₂ reaction system. It is shown that the island size of a few microns increases while the island density decreases with growth temperature. The saturation island density is found to be 10⁴–10⁸ cm^-2 and increases exponentially with the reciprocal of the growth temperature. The difference between the island saturation phenomenon that we observed and that described by the present nucleation theories may involve a smaller supersaturation in the vapour phase and the molecular diffusion of associated species on the molybdenum surface.     

Zinc blende and wurtzite crystal phase mixing and transition in indium phosphide nanowires

Indium phosphide (InP) nanowires, which have crystal phase mixing and transition from zinc blende (ZB) to wurtzite (WZ), are grown in intermediate growth conditions between ZB and WZ by using selective-area metalorganic vapor phase epitaxy (SA-MOVPE). The shape of InP nanowires is tapered unlike ZB or WZ nanowires. A growth model has been developed for the tapered nanowires, which is simply described as the relationship between tapered angle and the ratio of ZB and WZ segments. In addition, the peak energy shift in photoluminescence measurement was attributed to the quantum confinement effect of the quantum well of the ZB region located in the polytypic structure of ZB and WZ in nanowires.     

Growth and characterization of indium phosphide nanowires on transparent conductive ZnO:Al films

The epitaxial growth of indium phosphide nanowires (InP NWs) on transparent conductive aluminum-doped zinc oxide (ZnO:Al) thin films is proposed and demonstrated. ZnO:Al thin films were prepared on quartz substrates by radio frequency magnetron sputtering, then InP NWs were grown on them by plasma enhanced metal organic chemical vapor deposition with gold catalyst. Microstructure and optical properties of InP nanowires on ZnO:Al thin films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectric spectroscopy (XPS), photoluminescence and Raman spectroscopy at room temperature. SEM shows that randomly oriented and intersecting InP nanowires were grown to form a network on ZnO:Al thin films. Both wurtzite (WZ) and zincblende (ZB) structures coexist in the random orientation InP NWs on ZnO:Al thin film had been proved by XRD analysis. XPS result indicates Zn diffusion exists in the InP NWs on ZnO:Al. The photoluminescence spectra of InP nanowires with Zn diffusion present an emission at 915 nm. Zn diffusion also bring effect on Raman spectra of InP NWs, leading to more Raman-shift and larger relative intensity ratio of TO/LO.     

基于气液固机理的大批量InN纳米线生长

采用气液固机理生长了大批量均匀的InN纳米线,扫描电镜图像显示出这些光滑纳米线的平均直径和长度分别为65nm和15μm。高分辨透射电镜、选区电子衍射、微区拉曼散射光谱结合EDS能谱说明了纳米线为六方纤锌矿结构单晶,并证实了纳米线的生长遵循气液固生长机理。纳米线的光致发光光谱在1.89eV附近有一发光峰。改变NH3的流量可以调控纳米线的形貌和生长方向,我们从能量角度对此进行了解释。     

Heteroepitaxial growth of indium phosphide on silicon by MOCVD using adduct source

Abstract

The heteroepitaxial growth of InP on Si by low pressure metalor‐ganic chemical vapor deposition is reported. Trimethylindium‐trimethylphosphine adduct was used as In source in this study. From X‐ray and SEM examinations, good crystallinity InP epilayers with mirror‐like surfaces can be grown directly on (100) and (111) p‐type Si substrates. Carrier concentration profile shows that the carrier distribution in the InP epilayer is very uniform. The efficient photo‐luminescence compared with that of InP homoepitaxy shows the good quality of InP/Si epilayers.     

Impurities in single crystal indium phosphide

The impurity concentrations in present low carrier concentration indium phosphide single crystals (N _D-N _A=2×10¹⁵ to 5×10¹⁵cm^–3) grown by the Czochralski technique have been measured by spark-source mass spectrometry and radio-gamma activation analysis and compared with both the polycrystalline source material and the excess indium produced during compounding and growth. The predominant impurities are shown to be carbon, oxygen and silicon but the segregation of lesser impurities into the excess indium has allowed some nineteen other elements which are likely to be present in indium phosphide to be identified. No consistent correlation is evident between the measured concentration of specific impurities and the ionized donor (N _D) and acceptor (N _A) impurity levels as determined from the free-electron concentration (N _D-N _A) and Hall mobility at 77 K using the Brooks-Herring theory.     

Surface features on zinc-diffused indium phosphide

When zinc is diffused into indium phosphide, interesting features are sometimes observed on the surface of the semiconductor at the end of the diffusion. In the work to be described, the experimental conditions necessary to produce these feaures were investigated and the features were observed using the techniques of optical microscopy, scanning electron microscopy, and X-ray microprobe analysis. Two different types of feature were identified, one zinc-rich and the other indium-rich. Some experiments were carried out using radio-tracer zinc so that diffusion profiles of zinc in the indium phosphide could be plotted. It was found that experimental conditions that gave rise to surface features also produced very high surface concentrations of zinc. An attempt is made to explain the results using a proposed In/P/Zn phase diagram.     

Surface activation of colloidal indium phosphide nanocrystals

Against general wisdom in crystallization,the nucleation of InP and Ⅲ-Ⅴ quantum dots (QDs) often dominates their growth.Systematic studies on InP QDs identified the key reason for this:the dense and tight alkanoate-ligand shell around each nanocrystal.Different strategies were explored to enable necessary ligand dynamics—i.e.,ligands rapidly switching between being bonded to and detached from a nanocrystal upon thermal agitation—on nanocrystals to simultaneously retain colloidal stability and allow appreciable growth.Among all the surface-activation reagents tested,2,4-diketones (such as acetylacetone) allowed the full growth of InP QDs with indium alkanoates and trimethylsilylphosphine as precursors.While small fatty acids (such as acetic acid) were partially active,common neutral ligands (such as fatty amines,organophosphines,and phosphine oxides) showed limited activation effects.The existing amine-based synthesis of InP QDs was activated by acetic acid formed in situ.Surface activation with common precursors enabled the growth of InP QDs with a distinguishable absorption peak between ～450 and 650 nm at mild temperatures (140-180 ℃).Furthermore,surface activation was generally applicable for InAs and Ⅲ-Ⅴ based core/shell QDs.     

The structure of silver contacts on indium phosphide

Ag electrical contacts made to (001)InP were investigated. The sintering of these contacts at temperatures around 400 °C does not produce any intermetallic compound detectable by transmission electron microscopy. It does result in a recrystallization of the Ag epitaxially oriented with respect to the InP. The single positioning of this epitaxy suggests that the bond is made to an (001)In surface of the InP.     

Material flow under an indentor in indium phosphide

Single crystals of indium phosphide, oriented in the 001 direction and at the temperature of 400 °C, have been deformed by a Vickers indentor. The generation and the development of the dislocations was deduced from the topographical observations of the deformed samples. The dislocation distribution under the indented surface was explained taking into account the dislocation interactions. Finally, both aspects have allowed a greater understanding of material flow under the indentor to be presented.     

Etch features in Czochralski-grown single crystal indium phosphide

Two etchants for InP have been used to categorize etch features in both horizontal and vertical sections of InP single crystals grown by the Czochralski liquid encapsulation technique; these are the AB etchant, used extensively for defect analysis in GaAs and another etchant based on a phosphoric acid/hydrobromic acid mixture. The behaviour of these etchants is different but a cross correlation has been made between the types of etch feature produced. Transmission X-ray topography has been used to correlate etch features with dislocations. Nominally undoped crystals and material doped with specific impurities, e.g. Fe, Ge, Zn, have been examined. The principal features produced by etching are pits, ridges and striations. It is shown that the density and distribution of pits and ridges is consistent with these features being dislocation structures and the mechanisms by which they are revealed are discussed in terms of etching rates. The results allow comment to be made upon interface shape and the source of dislocations in InP crystals grown by the Czochralski technique.     

A study of vapour phase epitaxy of indium phosphide

The results of a study of the preparation of epitaxial layers of indium phosphide on indium phosphide substrates by means of the PCl₃-In-InP process are presented. The limitations of the process as discovered in this study are described. It is proposed that the major reaction species is phosphine and the unpredictable break-down of this compound, along with the presence of oxyhalides in the phosphorus trihalides, are the significant causes of the observed variation of the parameters of the epitaxial layers.     

An investigation of gold-zinc contacts on n-type indium phosphide

Experiments are described in which Schottky-type diodes were made by evaporating metal dots onto indium phosphide prepared by liquid phase epitaxy. Three types of metal dot were studied, one consisting of 2000 Å of gold, one of 2000 Å of a gold-zinc alloy and one composed of a layer of gold 2000 Å thick on a layer of zinc 1000 Å thick. The currents passed by the diodes under reverse bias and the capacitance-voltage characteristics were measured. Annealing treatments were applied to all specimens. It was found that the first two types of specimen deteriorated on annealing while the electrical properties of the third improved. Secondary ion mass spectroscopy was applied to specimens of all three types and the electrical results were interpreted in terms of the distribution of elements within a specimen.     

Vapour phase preparation of indium phosphide in large quantities

Several chemical reactions are investigated with the objective of producing indium phoshide in a form suitable for single crystal growth. The most suitable reaction for this purpose and the nature and quality of the product are described.     

The preparation of indium phosphide layers by chloride-hydride reactions

The preparation of indium phosphide by reactions between separate indium chlorides and phosphine is described. It is shown that the indium monochloride-phosphine reaction is the most favourable of the three possible reactions. It is demonstrated that various growth rates are possible over a range of temperatures, that good morphological layers can be obtained along with reasonable electrical characteristics. Explanations are advanced for the chemical process and the limitations on layer properties encountered.