Hydrogen Passivation of Interfacial Defects in MOCVD grown GaAs/InP

1989 ◽  
Vol 163 ◽  
Author(s):  
V. Swaminatan ◽  
U. K. Chakrabarthi ◽  
W. S. Hobson ◽  
R. Caruso ◽  
J. Lopata ◽  
...  
Keyword(s):  
Lattice Mismatch ◽  
Hydrogen Plasma ◽  
Chemical Vapor ◽  
Fold Increase ◽  
Peak Shift ◽  
Organic Chemical ◽  
Interfacial Region ◽  
Band Edge Emission ◽  
Hydrogen Passivation ◽  
Untreated Sample

AbstractThe results of a low temperature (5K) photoluminescence study of hydrogenation of GaAs on InP grown by metal organic chemical vapor deposition are presented. An emission band at ~ 1.4 eV originating from the GaAs/InP interracial region shows a 30 fold increase in intensity relative to the GaAs band edge emission after exposure to hydrogen plasma for 30 min at 250°C. This improvement in intensity is attributed to hydrogen passivation of defects at the heterointerface caused by the large (≈4%) lattice mismatch between GaAs and InP. The passivation effect recovers on annealing the hydrogenated sample at 350°C. Excitation dependence of the ~1.4 eV band suggests that the interfacial region consists of a compositionally graded layer. Further, this band shifts to higher energy on annealing the sample in the temperature range 150-450°C with the hydrogenated sample exhibiting a larger shift than the untreated sample. It is suggested that the annealing induced peak shift arises due to intermixing of the compositionally graded interface and that the degree of intermixing is greater in the hydrogenated sample compared to the untreated sample.

Behavior of Deep Defects After Hydrogen Passivation in Znte Studied by Photoluminescence and Photoconductivity

1998 ◽  
Vol 510 ◽  
Author(s):  
S. Bhunia ◽  
D.N. Bose
Keyword(s):  
Thermal Activation ◽  
Hydrogen Plasma ◽  
Minority Carrier Lifetime ◽  
Activation Energies ◽  
Band Edge ◽  
Band Edge Emission ◽  
Hydrogen Passivation ◽  
Deep Acceptor ◽  
Strong Band ◽  
Deep Acceptor Level

AbstractThe effects of hydrogen passivation in undoped p-ZnTe single crystals were studied by photoluminescence (PL) and photoconductivity (PC) measurements. Samples were exposed to r.f hydrogen plasma at 250 °C for different durations. Before passivation PL peaks were observed at 2.06 eV, 1.47 eV, 1.33 eV and 1.06 eV. After 60 minutes exposure, samples showed strong band edge green luminescence at 2.37 eV due to an exciton bound to a Cu acceptor. Further exposure to plasma resulted in disappearance of 2.37eV and 2.34 eV peaks due to damage. In PC studies the dark current was found to decrease by a factor of 70 on 60 minutes passivation. From the temperature dependence of PC gain, the minority carrier lifetime τn, was found to go through a maximum of 4.5 × 10−7 sec at 220 K before passivation. After 60 minutes exposure, τn, remained constant at 4.5 × 10−7 sec for T > 220 K and decreased for T < 220 K. The activation energies of τn, were determined and show marked changes on passivation for T > 220 K. Comparison between PL and PC studies showed that the deep acceptor level OTe responsible for emission at 2.06 eV is passivated giving rise to strong band edge emission at 2.37 eV while emission due to the midgap impurity levels at 1.47, 1.33 and 1.05 eV remained unaffected. The thermal activation energies of the PL peaks have also been determined and allow the construction of a defect energy level diagram for ZnTe.

The formation mechanism of planar defects in compound semiconductors grown epitaxially on {100} silicon substrates

1989 ◽  
Vol 4 (4) ◽  
pp. 834-842 ◽  
Author(s):  
F. Ernst ◽  
P. Pirouz
Keyword(s):  
Chemical Vapor Deposition ◽  
Formation Mechanism ◽  
Vapor Deposition ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Compound Semiconductors ◽  
Organic Chemical ◽  
Minor Role ◽  
Silicon Substrates ◽  
Wide Range

Films of three compound semiconductors with the zincblende structure grown epitaxially on {100} silicon substrates by chemical vapor deposition or metal-organic chemical vapor deposition were investigated by transmission electron microscopy. The three systems have similar thermal mismatches but cover a wide range of lattice mismatch. From the comparison of the observed microstructures as well as from the investigation of early stages of film formation it is concluded that the lattice mismatch plays a minor role in the formation of stacking faults and twin boundaries. A formation mechanism is proposed for these defects which is based on deposition errors during the adsorption of atoms on {111} facets of film nuclei. The observed microstructural features are discussed in terms of this model.

scholarly journals Исследование однородности состава по толщине слоев GaInAsP, полученных на подложках InP методом газофазной эпитаксии

2019 ◽  
Vol 53 (11) ◽  
pp. 1512
Author(s):  
Г.С. Гагис ◽  
Р.В. Левин ◽  
А.Е. Маричев ◽  
Б.В. Пушный ◽  
М.П. Щеглов ◽  
...  
Keyword(s):  
Epitaxial Layer ◽  
Lattice Mismatch ◽  
Crystal Surface ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Epitaxial Layers ◽  
Crystal Perfection ◽  
Vapor Phase Deposition ◽  
Low Degree ◽  
Metal Organic

GaInPAs/InP heterostructures grown by low pressure (0.1 bar, 600 oC) metal-organic chemical vapor phase deposition were investigated. The thicknesses of grown GaInAsP layers were about 1 µm. For the epitaxial layers Ga<sub>1-x</sub>In<sub>x</sub>P<sub>1-y</sub>As<sub>y)</sub> with average compositions of x = 0.77 – 0.87 and y = 0.07 – 0.42 the variation of V group elements content y with the epilayer depth were revealed, weher the compositions of V-group elements were changed up to Δy = 0.1 atomic fractions in V group elements sublattice. In most cases, y change occurs in a GaInAsP region up to 200 nm thick adjacent to the InP. In some cases, y changes throughout the whole GaInPAs layer thickness. Fo the epitaxial layers with a satisfactory crystal perfection the less was the mismatch between the substrate and the GaInPAs epitaxial layer, the smaller was the value of Δy. For GaInPAs layers characterized by a low degree of crystal perfection and a high lattice mismatch between GaInAsP and InP layers, the value of Δy was about zero. These data let us suggest that the incorporation of atoms of the V group in the epitaxial layer strongly depends on elastic deformation of the growing monolayer, that is mismatched with the underlying crystal surface.

High-operating-temperature MWIR photodetector based on a InAs/GaSb superlattice grown by MOCVD

2022 ◽  
Vol 43 (1) ◽  
pp. 012303
Author(s):  
Xiujun Hao ◽  
Yan Teng ◽  
He Zhu ◽  
Jiafeng Liu ◽  
Hong Zhu ◽  
...  
Keyword(s):  
Lattice Mismatch ◽  
Operating Temperature ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Cutoff Wavelength ◽  
X Ray Diffraction ◽  
High Crystalline Quality ◽  
High Operating Temperature ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

Abstract We demonstrate a high-operating-temperature (HOT) mid-wavelength InAs/GaSb superlattice heterojunction infrared photodetector grown by metal–organic chemical vapor deposition. High crystalline quality and the near-zero lattice mismatch of a InAs/GaSb superlattice on an InAs substrate were evidenced by high-resolution X-ray diffraction. At a bias voltage of –0.1 V and an operating temperature of 200 K, the device exhibited a 50% cutoff wavelength of ~ 4.9 μm, a dark current density of 0.012 A/cm2, and a peak specific detectivity of 2.3 × 109 cm·Hz1/2 /W.

scholarly journals Carrier Dynamics in InGaN/GaN on the Basis of Different In Concentrations

2019 ◽  
Vol 9 (11) ◽  
pp. 2279
Author(s):  
Zhi Ye ◽  
Hong Nguyen ◽  
Shih-Wei Feng ◽  
Hsiang-Chen Wang ◽  
Hwei-Ling Chou
Keyword(s):  
Strain Relaxation ◽  
Chemical Vapor ◽  
Fold Increase ◽  
Layer Growth ◽  
Lateral Strain ◽  
Organic Chemical ◽  
Time Resolved ◽  
Dislocation Reduction ◽  
Metal Organic ◽  
Sample Structure

InGaN/GaN samples grown on c-plane sapphire substrate with different In concentrations by metal organic chemical vapor deposition are demonstrated. The subsequent capping GaN layer growth opens a possibility for dislocation reduction due to the lateral strain relaxation in growth geometry. We present the further growth optimization and innovative characterization of InGaN layers overgrown on different structures with varying In concentrations. The photoelectrical and optical properties of the InGaN layers with/without capping GaN layer are investigated by time-resolved picosecond transient grating and temperature dependence photoluminescence. We note a 10-fold increase in carrier lifetime in the InGaN layers when the sample structure changed from PIN to single InGaN layer.

scholarly journals Production of Strontium Sulfide Coatings by Metal Organic Chemical Vapor Deposition

1998 ◽  
Vol 508 ◽  
Author(s):  
T.S. Moss ◽  
R.C. Dye ◽  
R.T. Tuenge
Keyword(s):  
Scale Up ◽  
Chemical Vapor ◽  
Fold Increase ◽  
Outer Radius ◽  
Small Scale ◽  
Thickness Variation ◽  
Organic Chemical ◽  
Strontium Sulfide ◽  
Organic Reagents ◽  
Metal Organic

AbstractThis work was focused on the MOCVD of the cerium-doped strontium sulfide (SrS:Ce) phosphor for use in thin film electroluminescent displays (TFELs). Following previous research on a small scale reactor, a feasibility scale-up using a commercially available reactor enlarged the size of the deposition area to a 4” diameter wafer or a 2” by 2” glass slide. Films were deposited from the reaction of Sr(thd)2, Ce(thd)4, and H2S at 450 °C and 5 torr. This system employed a liquid delivery system for the accurate and repeatable delivery of the metal organic reagents. The deposition from this reactor was shown to be crystalline-as-deposited SrS with a (200) orientation, possibly a result of the thin nature of the coating and the involvement of (200) grains in the initial nucleation process. The wafers showed good uniformity, but had some thickness variation near the outer radius of the wafer resulting from the addition of H2S from the outside edge. There were eighteen total deposition experiments, of which nine were characterized for EL performance. The highest brightness observed was 5 fL. The samples were exceedingly thin as a result of the fifteen fold increase in the surface area between the deposition reactors. Increasing the sample thickness to 7,000 Å or higher will dramatically increase the brightness of the emission.

Variant structure in metal-organic-chemical-vapor-deposition-derived SnO2 thin films on sapphire (0001)

1995 ◽  
Vol 10 (6) ◽  
pp. 1516-1522 ◽  
Author(s):  
Donhang Liu ◽  
Q. Wang ◽  
H.L.M. Chang ◽  
Haydn Chen
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Metal Organic ◽  
Film Substrate ◽  
Organic Chemical Vapor Deposition

Tin oxide (SnO2) thin films were deposited on sapphire (0001) substrate by metal-organic chemical vapor deposition (MOCVD) at temperatures of 600 and 700 °C. The microstructure of the deposited films was characterized by x-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). At the growth conditions studied, films were single-phase rutile and epitaxial, but showed variant structures. Three distinct in-plane epitaxial relationships were observed between the films and the substrate. A crystallographic model is proposed to explain the film morphology. This model can successfully predict the ratio of the width to the length of an averaged grain size based upon the lattice mismatch of the film-substrate interface.

High Temperature X-Ray Diffraction Study of PbTio3 Thin Films Grown on Mgo(001) by MOCVD

1995 ◽  
Vol 415 ◽  
Author(s):  
R.S. Batzer ◽  
Biming Yen ◽  
Donhang Liu ◽  
H. Kubo ◽  
G.R. Bai ◽  
...  
Keyword(s):  
Lattice Mismatch ◽  
Diffraction Method ◽  
Chemical Vapor ◽  
Transformation Strain ◽  
Temperature Cycling ◽  
Film Stress ◽  
Organic Chemical ◽  
Domain Formation ◽  
X Ray Diffraction ◽  
X Ray

ABSTRACTLead titanate (PT) is ferroelectric in its tetragonal phase (c/a=1.06). The domain formation is coupled to the relaxation of internal stress generated by a combination of lattice mismatch, transformation strain and differential thermal stress. The mechanism of domain formation in an epitaxially grown PT film is related to the substrate type and the growth temperature. In this study, PT films have been deposited on MgO(001) in a coldwall, horizontal metal organic chemical vapor deposition (MOCVD) system. The structure of domains and their evolution have been measured as a function of temperature by the x-ray diffraction method using a hot stage. Domain structure changes were observed by θ−2θ scans, ω scans, as well as in-plane φ scans. Effect of film stress on the ferroelectric transition temperature is discussed. Reproducibility of domain formation as a result of temperature cycling both below and above Tc is assessed.

Suppression of Antiphase Disorder in GaAs Grown on Relaxed GeSi Buffers by Metal-Organic Chemical Vapor Deposition

1998 ◽  
Vol 510 ◽  
Author(s):  
S. M. Ting ◽  
Srikanth B. Samavedam ◽  
Matthew T. Currie ◽  
Thomas A. Langdo ◽  
E. A. Fitzgerald
Keyword(s):  
Phase Transitions ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Complete Suppression ◽  
Nonradiative Recombination ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

AbstractDue to the prohibitively high 4.1% lattice mismatch, direct growth of GaAs on Si invariably leads to very high dislocation densities (> 108/cm2) which have precluded its use in device applications despite numerous attempts. However, the growth of low threading dislocation density (∼2 × 106/cm2) relaxed graded Ge/GexSi1−x/Si heterostructures can bridge the gap between lattice constants by replacing the high mismatch GaAs/Si interface with a low mismatch (< 0.1%) GaAs/Ge interface. Although the lattice mismatch problem is thus eliminated, the heterovalent GaAs/Ge interface remains highly susceptible to antiphase disorder. Since antiphase boundaries (APBs) nucleated at the GaAs/Ge interface act as scattering and nonradiative recombination centers, growth of device quality GaAs on Ge/GexSi1−x/Si demands effective suppression of antiphase disorder. The current work investigates the sublattice location of GaAs on 6° offcut (001) Ge/GexSi1−x/Si substrates as a function of atmospheric pressure metal-organic chemical vapor deposition (MOCVD) growth initiation parameters. Two distinct GaAs phases are observed, one dominant at temperatures > 600°C and another at temperatures <500°C. Incomplete phase transitions during pre-growth thermal cycling account for the appearance of localized bands of anti-phase disorder where the polarity of the GaAs film switches. We suspect that background arsenic levels in the MOCVD system are largely responsible for inducing the observed phase transitions. The complete suppression of antiphase disorder under optimized growth conditions is demonstrated by transmission electron microscopy (TEM)

scholarly journals Influence of InxGa1-xAs Underlying Layer on the Structural of the In0.5Ga0.5As Quantum Dots Grown by MOCVD

2014 ◽  
Vol 7 (1) ◽  
Author(s):  
D. Aryanto ◽  
Z. Othaman ◽  
A. K. Ismail ◽  
A. S. Ameruddin
Keyword(s):  
Quantum Dots ◽  
Lattice Mismatch ◽  
Single Layer ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Force Microscopy ◽  
Indium Composition ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Surface Changes

The single layer In0.5Ga0.5As quantum dots (QDs) were grown on a thin InxGa1-xAs underlying layer by metal-organic chemical vapor deposition(MOCVD) via Stranski-Krastanow growth mode. The effect of different indium composition in the InxGa1-xAs underlying layer was investigated usingatomic force microscopy (AFM). AFM images show that the QDs structures were formed on the surface. The dots formation on the surface changes withdifferent composition of InxGa1-xAs underlying layer. Increasing indium composition in the underlying layer resulted to formation of higher density andsmaller size dots. Several large dots were also formed on the surface. Growing of underlying layer reduces the lattice mismatch between In0.5Ga0.5As andGaAs, and decreases the critical thickness of the dots. This strongly influences the dots nucleation on the surface. Growth of quantum dots usingunderlying layer is one way to modify dot formation in order to achieve uniform QDs of right size and high density, which are essential for QDs deviceapplications.

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