Indium Phosphide Crystals Research Articles

Dislocation reduction in sulfur- and germanium-doped indium phosphide single crystals grown by the vertical gradient freeze process: A transient finite-element study

During the growth of indium phosphide (InP) crystals, dislocations are mostly generated in a plastically deformed crystal due to crystallographic glide caused by excessive thermal stresses. High dislocation density presented in the InP crystal can reduce the performance, lifetime, and reliability of the InP-based microelectronic and optoelectronic devices/circuits. The generation of dislocations in InP single crystals grown from the melt can be predicted by using a transient finite-element model. This model couples microscopic dislocation motion and multiplication to macroscopic plastic deformation during the crystal growth process. The temperature fields in the crystal are determined by solving the partial differential equations of heat transfer for the vertical gradient freeze (VGF) process. These temperature fields are then employed to the transient finite-element model to study the effects of doping impurities and growth parameters (i.e., imposed temperature gradient, crystal radius, and growth rate) on dislocation reduction in InP crystals grown by different VGF processes.

The Effect of Treatment in a Pulsed Magnetic Field on the Kinetics of Oxidation of Indium Phosphide Crystals

It is demonstrated that preliminary treatment of semiconductors (for example, indium phosphide) in a pulsed magnetic field can increase the rate of surface chemical reactions (in particular, oxidation).

Growth of co-doped semi-insulating indium phosphide crystals for X-ray detection

Co-doped indium phosphide crystals were grown by liquid encapsulated Czochralski technique for application in X-ray detection. Semi-insulating state was created by iron–zinc, titanium–zinc and titanium–manganese co-doping using one or two stage growth procedure. Crystals were characterized by temperature-dependent resistivity and Hall coefficient measurements. The resistivity of InP(Fe,Zn) was 5.8×10 7 Ω cm, of InP(Ti,Zn) was 3.7×10 5 Ω cm and of InP(Ti,Mn) was 2.2×10 6 Ω cm.

Lightwave single sideband wavelength self-tunable filter using an InP:Fe crystal for fiber-wireless systems

A new optical single sideband filter is presented to compensate for chromatic dispersion effects in fiber-wireless systems. The device is based on three dynamic Bragg gratings, which are generated in a photorefractive iron-doped indium phosphide (InP:Fe) crystal. This filter is controlled by the input optical double sideband signal itself, which makes it independent of the modulated optical carrier wavelength. In this paper, the principle of the device is presented and demonstrated. Experiments include a 14-km fiber transmission followed by a 3-m radio link carrying a 140-Mb/s binary phase-shift keyed data stream at 16 GHz.

Effect of growth parameters on dislocation generation in InP single crystal grown by the vertical gradient freeze process

The generation and multiplication of dislocations in an indium phosphide (InP) single crystal grown by the vertical gradient freeze (VGF) process is predicted using a crystallographic model. This model couples microscopic dislocation motion and multiplication to macroscopic plastic deformation during the crystal growth process. During growth of an InP crystal, dislocations are generated in the plastically deformed crystal as a result of crystallographic glide caused by excessive thermal stresses. The temperature fields are determined by solving the partial differential equation of heat conduction in a VGF crystal growth system. The effects of growth direction and growth parameters (i.e. imposed temperature gradients, crystal radius and growth rate) on dislocation generation and multiplication in an InP crystal are investigated. Dislocation density patterns on the cross section of an InP crystal are numerically calculated and compared with experimental observations.

Forced Convection During Liquid Encapsulated Crystal Growth With an Axial Magnetic Field

This paper treats the forced convection, which is produced by the rotation of the crystal about its vertical centerline during the liquid-encapsulated Czochralski or Kyropoulos growth of compound semiconductor crystals, with a uniform vertical magnetic field. The model assumes that the magnetic field strength is sufficiently large that convective heat transfer and all inertial effects except the centripetal acceleration are negligible. With the liquid encapsulant in the radial gap between the outside surface of the crystal and the vertical wall of the crucible, the forced convection is fundamentally different from that with a free surface between the crystal and crucible for the Czochralski growth of silicon crystals. Again unlike the case for silicon growth, the forced convection for the actual nonzero electrical conductivity of an indium-phosphide crystal is virtually identical to that for an electrically insulating crystal. The electromagnetic damping of the forced convection is stronger than that of the buoyant convection. In order to maintain a given balance between the forced and buoyant convections, the angular velocity of the crystal must be increased as the magnetic field strength is increased.

Annealing Behavior of the Hydrogen-Vacancy Complex in Bulk Indium Phosphide Crystals

ABSTRACTIn order to explain the effects of hydrogen on the electrical properties of bulk indium phosphide crystals, we have performed a series of high temperature annealing studies with both undoped and iron-doped indium phosphide crystals. Our samples were annealed at 900°C for 6, 36, and 72 hours, respectively, under a phosphorus overpressure of five atmospheres. Samples were characterized at 10 K by Fourier transform infrared absorption spectroscopy which allowed us to measure the concentrations of both the Fe2+ and VIn-H4 defects simultaneously. Undoped samples were further characterized by the Hall effect measurements. We find in the iron-doped samples that the [Fe2+]/[Fe3+] ratio decreases gradually with increasing annealing time, indicating a reduction in the number of donors in the samples. In the undoped samples, annealing leads to a reduction of the free electron concentration accompanied by an increase in the 77 K mobility. The increase of the sample's mobility eliminates the possibility that the reduction of the free electron concentration is due to an increase in the concentration of the compensating acceptors. Our explanation for the observed behavior in all samples is that hydrogen acts as a donor and it diffuses out of the crystal during the annealing process. Based on our experimental data, we propose a calibration equation of [VIn-H4] = 4.2×1016 cm−1 × Absorbance (cm−1) which is used to correlate the hydrogen-vacancy complex concentrations with the changes of the VIn-H4 absorption peak in both the iron-doped and the undoped samples. Our results confirm the donor nature of the hydrogen-vacancy complex and provide strong evidence regarding the reduction mechanism of free carrier concentrations in bulk indium phosphide crystals during high temperature annealing under a phosphorus atmosphere.

Material Flow at the Surface of Indented Indium Phosphide

Single crystals of indium phosphide oriented in the (001) direction have been deformed by microhardness indentation. The surface topography was observed by interferential optical microscopy and scanning electron microscopy in the secondary electron mode. The dislocation distribution and their nature at the surface were investigated by scanning electron microscopy in the cathodoluminescent mode and transmission electron microscopy. Both observations have led us to a better understanding of the material flow at the surface sample when it is indented.

Transport phenomena in a high pressure crystal growth system: In situ synthesis for InP melt

The physical phenomena underlying the “one-step” in situ synthesis and high pressure growth of indium phosphide crystals are complex. A high resolution computer model based on multizone adaptive grid generation and curvilinear finite volume discretization is used to predict the flow and temperature fields during the synthesis of the InP melt. Simulations are performed for a range of parameters, including Grashof number, crucible rotation, and location of the injector. These parameters affect the gas flow in a high pressure liquid-encapsulated Czochralski (HPLEC) furnace significantly, and have a strong influence on the melt synthesis and its control.

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.

Evaluation of semi-insulating InP crystals for nuclear radiation

We present a preliminary study of the performance of semi-insulating indium phosphide (InP) crystals and its possible use in nuclear radiation detection at room temperature. Devices having an active area of 12 mm 2 showed a 5% resolution (FWHM) for 5.48 MeV alpha particles. Analyses of photo spectra indicated that the trapping of holes was primarily responsible for degrading the alpha response.

A multizone adaptive process model for low and high pressure crystal growth

Many of the inhomogeneities and defects in the crystal grown from a pool of melt are a direct result of the non-steady nature of the growth kinetics and complex heat transfer and flow mechanisms. The transport phenomena become more complicated in a high pressure system because of the thermal interaction between melt and gas flows, and require special numerical treatment. A high resolution computer model based on multizone adaptive grid generation and curvilinear finite volume discretization (MASTRAPP2d) has been developed to simulate the crystal growth processes at low and high pressures. The scheme allows consideration of a multiphase system for more than one material in one single domain which may consist of irregular and moving boundaries, interfaces, and free surfaces. Cz growth of silicon and LEC growth of indium phosphide crystals are modeled to demonstrate the robustness and effectiveness of this innovative scheme.

First tunable narrowband 1.55 µm optical drop filter using a dynamic photorefractive grating in iron doped indium phosphide

A tunable narrowband (FWHM=2.5 GHz) 1.55 mu m reflective drop filter is realised in an iron doped indium phosphide crystal. The index grating results from the photorefractive effect via an interference pattern. The grating period is determined by the wavelength of the laser diode which provides the two counter-propagating writing beams.

Thermal characterization of the high pressure crystal growth system for in-situ synthesis and growth of InP crystals

Indium phosphide (InP) is an important substrate material for light-wave communications, opto-electronics and radiation-resistant solar cells. However, the high cost and low productivity of the current two-step InP crystal growth process remains a severe drawback to its commercial applications. This has motivated many researchers to propose and investigate an innovative scheme of one-step synthesis (by injecting phosphorus vapor into the indium melt) and growth of InP crystals by the liquid-encapsulated Czochralski or Kyropoulos technique. For this one-step process to succeed and produce single crystals of uniform quality, it is important to develop a basic understanding of the mechanisms of energy transport and gas flow in a high-pressure crystal growth (HPCG) system. A series of experiments is conducted to characterize the thermal coupling between the melt and the phosphorus injector and to develop an understanding of the buoyancy-induced flow in a HPCG furnace. The gas flow in a high pressure furnace is turbulent and oscillatory, but radiation dominates the heat transfer. Thermal response of the system is therefore quite stable and predictable. The correlation between temperatures at various locations of the phosphorus injector and the melt is very interesting. The heat of reaction also affects the melt temperature. The phase change phenomenon at the bottom of the phosphorus injector seems to be oscillatory in nature. Theoretical estimates of the strength of gas convection and radiation loss by the melt surface are also presented.

MLEK crystal growth of large diameter (100) indium phosphide

Twin-free single crystals of indium phosphide have been grown using the magnetic liquid encapsulated Kyropoulos (MLEK) method. The characteristic features of this growth method which distinguish it from standard LEC growth of InP, are the impurity distribution coefficient, the solid-liquid interface shape, and the dislocation density. InP crystals grown by both LEC and MLEK methods are compared to show the differences in growth characteristics on the microscale as well as on the macroscale.

MLEK crystal growth of (100) indium phosphide

We have used a combined magnetic liquid encapsulated Kyropoulos/Czochralski (MLEK/ MLEC) technique to produce twin-free indium phosphide (InP) crystals. This technique has advantages over the standard LEC method used for commercial production of InP. By stabilizing convective flows with a magnetic field and controlling the angle between solid and liquid, one can grow large diameter twin-free (100) InP crystals; they are shaped with a flat top as is typical for Kyropoulos growth, and then pulled from the magnetically stabilized melt as in Czochralski growth. This shaping method has the benefit of maximizing the number of single crystal wafers which can be sliced from the boule. MLEK InP growth is distinguished from other methods such as LEC and MLEC with respect to solid-liquid interface shape, dislocation density, and impurity distribution. This process has demonstrated that twin-free InP (100) crystals can be consistently grown.

Shaped crystal quality control using multiprobe methods

The solutions of Laplace's equations for potential and current distributions are analyzed in crystals shaped as a cylinder or a rectangular parallelepiped for the case where the contacts are located on the base or on the walls. Distributions of electrical parameters are calculated for indium phosphide crystals having a geometrical shape similar to that of a cylindrical section.

Spatial distribution of donors in silicon implanted iron and iron-gallium doped semi-insulating indium phosphide

Knowledge of the electrical activity of an implanted layer throughout wholly semi-insulating indium phosphide (InP) crystals provides a very useful indication of the crystal qualification for integrated circuit application. Different cartography techniques are studied to characterize various SI InP ingots: The mapping of sheet resistance and the scanning photoluminescence image are mainly performed. Standard iron doped SI InP crystals grown by LEC are used, as well as iron–gallium doped crystals and long annealed iron-doped crystals. Cartography techniques as well as different SI ingots are compared.

Analysis of precipitate phases in Fe-doped indium phosphide crystals

physica status solidi (a)Volume 113, Issue 1 p. K41-K43 Lattice Properties Analysis of precipitate phases in Fe-doped indium phosphide crystals L. F. Zakharenkov, L. F. Zakharenkov Department of Experimental Physics, M.I. Kalinin Polytechnical Institute, Leningrad Search for more papers by this authorV. F. Kobelev, V. F. Kobelev Department of Experimental Physics, M.I. Kalinin Polytechnical Institute, Leningrad Search for more papers by this authorA. Ya. Nikolaich, A. Ya. Nikolaich Department of Experimental Physics, M.I. Kalinin Polytechnical Institute, Leningrad Search for more papers by this authorV. A. Oparin, V. A. Oparin Department of Experimental Physics, M.I. Kalinin Polytechnical Institute, Leningrad Search for more papers by this author L. F. Zakharenkov, L. F. Zakharenkov Department of Experimental Physics, M.I. Kalinin Polytechnical Institute, Leningrad Search for more papers by this authorV. F. Kobelev, V. F. Kobelev Department of Experimental Physics, M.I. Kalinin Polytechnical Institute, Leningrad Search for more papers by this authorA. Ya. Nikolaich, A. Ya. Nikolaich Department of Experimental Physics, M.I. Kalinin Polytechnical Institute, Leningrad Search for more papers by this authorV. A. Oparin, V. A. Oparin Department of Experimental Physics, M.I. Kalinin Polytechnical Institute, Leningrad Search for more papers by this author First published: 16 May 1989 https://doi.org/10.1002/pssa.2211130137 Politekhnicheskaya 29, SU-195251 Leningrad, USSR. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume113, Issue116 May 1989Pages K41-K43 RelatedInformation

Measurement of charge-carrier concentration in indium phosphide by means of an electrolyte-semiconductor contact

An electrolyte-semiconductor contact is used to study the conductivity of epitaxial layers and single crystals of n-type indium phosphide obtained by gas transport. Some of the specimens were alloyed with tin and sulfur. The voltfarad characteristics are used to find the potentials of planar zones, which amount to 0.8–1.3 V for different electrolytes. Values of concentration of charge carriers calculated from measured values of capacitance of the electrolyte-indium-phosphide contact showed good agreement with measurements of the Hall effect on single crystals in the range 1016-1018cm−3. The use of measurements of the capacitance of the electrolyte-semiconductor contact with simultaneous etching of a local region made it possible to study the electron distribution in epitaxial layers of indium phosphide.