Optical and Electrical Properties of Al1−xInxN Films Grown on Sapphire (0001) by Plasma Source Molecular Beam Epitaxy

ABSTRACTA series of epitaxial InxAl1−xN alloy films (thickness ~ 150 nm) with 0 ≤ × ≤ 1.0 were grown by Plasma Source Molecular Beam Epitaxy (PSMBE) on sapphire (0001) at a low substrate temperature of 375 °C. X-ray diffraction (XRD) measurements confirm a c-axis oriented epitaxial growth of alloy films without any alloy segregation. However, the degree of crystalline mosaicity, compositional fluctuation and surface roughness, all increase with increasing x. The direct energy band gap of alloy films were determined using optical (UV-VIS) transmission and reflection measurements. The observed bowing of the direct gap versus x plot, when compared to the theoretical prediction, is less pronounced than seen in earlier studies reported in literature. Electrical resistivity and Hall effect measurements show n-type electrical conductivity in these alloys with carrier concentrations ~1019-1020 cm−3 for x > 0.5.

Download Full-text

Growth and Characterization of Epitaxial Al1−xInxN Films Grown on Sapphire (0001) by Plasma Source Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-639-g6.54 ◽

2000 ◽

Vol 639 ◽

Cited By ~ 1

Author(s):

M. J. Lukitsch ◽

G. W. Auner ◽

R. Naik ◽

V. M. Naik

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Plasma Source ◽

High Energy ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Alloy Segregation

ABSTRACTEpitaxial Al1−xInxN films (thickness ∼150 nm) with 0 ≤ × ≤ 1 have been grown by Plasma Source Molecular Beam Epitaxy on Sapphire (0001) at a low substrate temperature of 375°C and were characterized by reflection high energy electron diffraction (RHEED), x-ray diffraction (XRD), and atomic force microscopy (AFM). Both RHEED and XRD measurements confirm the c-plane growth of Al1-xInxN films on sapphire (0001) with the following epitaxial relations: Nitride [0001] ∥ Sapphire [0001] and Nitride < 0110 > ∥ Sapphire <2110>. The films do not show any alloy segregation. However, the degree of crystalline mosaicity and the compositional fluctuation increases with increasing In concentration. Further, AFM measurements show an increased surface roughness with increasing In concentration in the alloy films.

Download Full-text

Effects of Stress-relieving AlN Interlayers in GaN-on-Si Grown by Plasma-assisted Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-1068-c06-04 ◽

2008 ◽

Vol 1068 ◽

Author(s):

Adam Adikimenakis ◽

Suman-Lata Sahonta ◽

George Dimitrakopulos ◽

Jaroslav Domagala ◽

Philomela Komninou ◽

...

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Plasma Source ◽

Rf Plasma ◽

X Ray Diffraction ◽

Inversion Domain ◽

Transmission Electron ◽

Stress Relieving ◽

Gan On Si ◽

Inversion Domain Boundaries

ABSTRACTThe insertion of an AlN interlayer for tensile strain relief in GaN thin films grown on Si (111) on-axis and vicinal substrates by nitrogen rf plasma source molecular beam epitaxy has been investigated. The 15 nm AlN interlayer was inserted between the bottom 0.5 micron GaN layer and the top 1.0 micron GaN layer. The interlayer was very effective to reduce the tensile stress in the overall 1.5 micron GaN/Si film to the level required for complete avoidance of microcracks, which were present in high densities in GaN/Si heterostructures grown without an AlN interlayer. The strain of the AlN interlayer, as well as the strain in all the layers of the entire GaN/Si heterostructure was analyzed by x-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements. Reciprocal space map in XRD indicated that the 15 nm AlN interlayer was coherently strained with the GaN films. However TEM observations revealed that the AlN interlayer was partially relaxed in local regions. The AlN interlayer was also observed to interfere with the GaN growth process. In particular, above morphological features such as V-defects, GaN was overgrown with a large density of threading dislocations and inversion domain boundaries.

Download Full-text

InP Layers Grown by Molecular Beam Epitaxy at Low Substrate Temperature

MRS Proceedings ◽

10.1557/proc-241-265 ◽

1991 ◽

Vol 241 ◽

Cited By ~ 5

Author(s):

K. Xie ◽

C. R. Wie ◽

G. W. Wicks

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

X Ray Diffraction ◽

Temperature Dependent ◽

Double Crystal ◽

X Ray ◽

Hall Effect Measurements ◽

Phosphorus Source ◽

Substrate Temperatures

ABSTRACTInP layers were grown on semi-insulating InP wafer by molecular beam epitaxy (MBE) at low substrate temperatures (<200° C), using solid phosphorus source. We use x-ray diffraction, double crystal x-ray rocking curve, Auger electron spectroscopy, and temperature-dependent Van der Pauw and Hall effect measurements to characterize the as-grown and annealed InP layers. It is found that the InP layer is in poly-crystal state with excess P over 7 at%. The layers became single crystal after annealing above 400°C. The resistivity of the InP layer decreased from 60 Ωcm for an as-grown sample to 0.82 Ωcm after 400°C RTA annealing. The different role of excess P as compared to the role played by excess As in LT-GaAs is discussed based on the P properties.

Download Full-text

Epitaxial Growth of Zinc-Blende Ain by Plasma Source Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-570-297 ◽

1999 ◽

Vol 570 ◽

Cited By ~ 1

Author(s):

Margarita P. Thompson ◽

Gregory W. Auner ◽

Andrew R. Drews ◽

Tsvetanka S. Zheleva ◽

Kenneth A. Jones

Keyword(s):

Molecular Beam Epitaxy ◽

Electron Diffraction ◽

Molecular Beam ◽

Plasma Source ◽

High Energy ◽

Lattice Parameter ◽

High Energy Electron ◽

X Ray Diffraction ◽

X Ray ◽

Zinc Blende

ABSTRACTEpitaxial zinc-blende AIN films as thick as 2000Å were deposited on Si (100) substrates by plasma source molecular beam epitaxy (PSMBE). The metastable zinc-blende form of AIN was observed to occur when pulse d.c. power was supplied to the PSMBE hollow cathode source. Reflection High Energy Electron Diffraction (RHEED) showed that the films possess a four fold symmetry. X-Ray Diffraction (XRD) revealed two strong peaks corresponding to the (200) and (400) reflections from the zinc-blende AIN. The lattice parameter of the films was calculated to be approximately 4.373Å. TEM, performed on one of the films, revealed that the AIN is cubic, single crystalline and epitaxial with respect to the Si (100) substrate.

Download Full-text

Structural and Optical Properties of InAsSbBi Grown by Molecular Beam Epitaxy on Offcut GaSb Substrates

Photonics ◽

10.3390/photonics8060215 ◽

2021 ◽

Vol 8 (6) ◽

pp. 215

Author(s):

Rajeev R. Kosireddy ◽

Stephen T. Schaefer ◽

Marko S. Milosavljevic ◽

Shane R. Johnson

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Optical Quality ◽

X Ray Diffraction ◽

Interface Quality ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Lateral Variations

Three InAsSbBi samples are grown by molecular beam epitaxy at 400 °C on GaSb substrates with three different offcuts: (100) on-axis, (100) offcut 1° toward [011], and (100) offcut 4° toward [011]. The samples are investigated using X-ray diffraction, Nomarski optical microscopy, atomic force microscopy, transmission electron microscopy, and photoluminescence spectroscopy. The InAsSbBi layers are 210 nm thick, coherently strained, and show no observable defects. The substrate offcut is not observed to influence the structural and interface quality of the samples. Each sample exhibits small lateral variations in the Bi mole fraction, with the largest variation observed in the on-axis growth. Bismuth rich surface droplet features are observed on all samples. The surface droplets are isotropic on the on-axis sample and elongated along the [011¯] step edges on the 1° and 4° offcut samples. No significant change in optical quality with offcut angle is observed.

Download Full-text

Optical and structural prorerties of InAs epilayer on graded InGaAs

MRS Proceedings ◽

10.1557/proc-696-n3.10 ◽

2001 ◽

Vol 696 ◽

Author(s):

Gu Hyun Kim ◽

Jung Bum Choi ◽

Joo In Lee ◽

Se-Kyung Kang ◽

Seung Il Ban ◽

...

Keyword(s):

Molecular Beam Epitaxy ◽

Residual Strain ◽

Molecular Beam ◽

Lattice Mismatch ◽

Peak Position ◽

Excitation Intensity ◽

Total Thickness ◽

Ingaas Layer ◽

X Ray Diffraction ◽

X Ray

AbstractWe have studied infrared photoluminescence (PL) and x-ray diffraction (XRD) of 400 nm and 1500 nm thick InAs epilayers on GaAs, and 4 nm thick InAs on graded InGaAs layer with total thickness of 300 nm grown by molecular beam epitaxy. The PL peak positions of 400 nm, 1500 nm and 4 nm InAs epilayer measured at 10 K are blue-shifted from that of InAs bulk by 6.5, 4.5, and 6 meV, respectively, which can be largely explained by the residual strain in the epilayer. The residual strain caused by the lattice mismatch between InAs and GaAs or graded InGaAs/GaAs was observed from XRD measurements. While the PL peak position of 400 nm thick InAs layer is linearly shifted toward higher energy with increase in excitation intensity ranging from 10 to 140 mW, those of 4 nm InAs epilayer on InGaAs and 1500 nm InAs layer on GaAs is gradually blue-shifted and then, saturated above a power of 75 mW. These results suggest that adopting a graded InGaAs layer between InAs and GaAs can efficiently reduce the strain due to lattice mismatch in the structure of InAs/GaAs.

Download Full-text

X-Ray Diffraction Study of Rare Earth Epitaxial Structures Grown by MBE onto (111) GaAs

MRS Proceedings ◽

10.1557/proc-151-277 ◽

1989 ◽

Vol 151 ◽

Author(s):

W. R. Bennett ◽

R. F. C. Farrow ◽

S. S. P. Parkin ◽

E. E. Marinero

Keyword(s):

Rare Earth ◽

Molecular Beam Epitaxy ◽

Rare Earth Metal ◽

Molecular Beam ◽

Earth Metal ◽

Magnetic Ordering ◽

Metal Films ◽

X Ray Diffraction ◽

X Ray ◽

Strain Components

ABSTRACTWe report on the new epitaxial system LaF3/Er/Dy/Er/LaF3/GaAs (111) grown by molecular beam epitaxy. X-ray diffraction studies have been used to determine the epitaxial relationships between the rare earths, the LaF3 and the substrate. Further studies of symmetric and asymmetric reflections yielded the in-plane and perpendicular strain components of the rare earth layers. Such systems may be used to probe the effects of magnetoelastic interactions and dimensionality on magnetic ordering in rare earth metal films and multilayers.

Download Full-text

A Study on the Growth of Cubic GaN Films Using an AlGaAs Buffer Layer Grown on GaAs (100) by Plasma-Assisted Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-639-g3.46 ◽

2000 ◽

Vol 639 ◽

Author(s):

Ryuhei Kimura ◽

Kiyoshi Takahashi ◽

H. T. Grahn

Keyword(s):

Molecular Beam Epitaxy ◽

Buffer Layer ◽

Molecular Beam ◽

High Energy ◽

Rf Plasma ◽

Cubic Phase ◽

X Ray Diffraction ◽

X Ray ◽

Cubic Gan

ABSTRACTAn investigation of the growth mechanism for RF-plasma assisted molecular beam epitaxy of cubic GaN films using a nitrided AlGaAs buffer layer was carried out by in-situ reflection high energy electron diffraction (RHEED) and high resolution X-ray diffraction (HRXRD). It was found that hexagonal GaN nuclei grow on (1, 1, 1) facets during nitridation of the AlGaAs buffer layer, but a highly pure, cubic-phase GaN epilayer was grown on the nitrided AlGaAs buffer layer.

Download Full-text

Optical and Structural Properties of AlGaN/GaN Quantum Wells Grown by Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-537-g11.7 ◽

1998 ◽

Vol 537 ◽

Cited By ~ 1

Author(s):

Nicolas Grandjean ◽

Jean Massies ◽

Mathieu Leroux ◽

Marguerite Latigt ◽

Pierre Lefebvre ◽

...

Keyword(s):

Molecular Beam Epitaxy ◽

Quantum Wells ◽

Molecular Beam ◽

Stark Effect ◽

X Ray Diffraction ◽

X Ray ◽

Quantum Confined Stark Effect ◽

Sapphire Substrates ◽

Gan Buffer Layer ◽

Large Quantum

AbstractAIGaN/GaN quantum well (QWs) were grown on (0001) sapphire substrates by molecular beam epitaxy (MBE) using ammonia as nitrogen precursor. The Al composition in the barriers was varied between 8 and 27 % and the well thickness from 4 to 17 monolayers (MLs, 1ML = 2.59Å). X-ray diffraction (XRD) experiments are used to investigate the strain state of both the well and the barriers. The QW transition energy are measured by low temperature photoluminescence (PL). A large quantum confined Stark effect is observed leading to QW luminescence much lower than the emission line of the GaN buffer layer for well width above a certain critical thickness. The built-in electric field responsible for such a phenomenon is deduced from fit of the PL data. Its magnitude is of several hundred kV/cm and increases linearly with the Al composition.

Download Full-text