Effects of Helium Ion Implantation on the Optical and Crystal Properties of GaAs

1989 ◽  
Vol 147 ◽  
Author(s):  
R. C. Bowman ◽  
P. M. Adams ◽  
J. F. Knudsen ◽  
S. C. Moss ◽  
P. A. Dafesh ◽  
...  
Keyword(s):  
Electron Beam ◽  
Raman Scattering ◽  
X Ray Diffraction ◽  
Phonon Modes ◽  
Double Crystal ◽  
Damage Behavior ◽  
X Ray ◽  
Crystal Properties ◽  
Helium Ion ◽  
Different Levels

AbstractThe damage to GaAs crystals caused by helium ion implants has been monitored by changes in the Raman scattering phonon modes, double-crystal x-ray diffraction rocking curves, photoreflectance (PR), and electron beam electroreflectance (EBER) band edge transitions. As the implanted helium ion dose was increased, the various techniques revealed threshold damage behavior at very different levels. Although PR and EBER were the most sensitive to the defects created at the lowest ion doses, all techniques indicated substantial disorder for implants greater than 1014 ions/cm2.

Effects of Rapid Thermal Anneals on Boron Implanted GaAs

1988 ◽  
Vol 144 ◽  
Author(s):  
R. C. Bowman ◽  
P. M. Adams ◽  
M. H. Herman ◽  
S. E. Buttrill
Keyword(s):  
Electron Beam ◽  
Raman Scattering ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Lattice Strain ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
X Ray ◽  
Conventional Furnace

ABSTRACTRaman scattering, double-crystal x-ray diffraction, and electron beam electroreflectance have been used to assess the damage produced in undoped (100)-GaAs by boron ion implants and the influence of post-implant anneals. Both conventional furnace and rapid thermal annealing treatments were found to remove much of the lattice strain created by the implants. However, considerable disorder also remains after these anneals.

Micro-Raman Scattering Properties of Highly Oriented AlN Films

1998 ◽  
Vol 12 (19) ◽  
pp. 1963-1974 ◽  
Author(s):  
Ming S. Liu ◽  
K. W. Nugent ◽  
S. Prawer ◽  
L. A. Bursill ◽  
J. L. Peng ◽  
...  
Keyword(s):  
Aluminum Nitride ◽  
Raman Scattering ◽  
Film Plane ◽  
Phonon Confinement ◽  
X Ray Diffraction ◽  
Phonon Modes ◽  
X Ray ◽  
Transmission Electron ◽  
Scattering Geometry ◽  
Confinement Model

Micro-Raman scattering by highly oriented crystalline aluminum nitride has been measured. Phonon modes in AlN were identified in different scattering geometry configurations and scattering polarizations. The phonon modes revealed that aluminum nitride films are highly oriented with the wurtzite c-axis direction normal to the film plane. The Raman scattering modes are broadened and shifted due to grain boundaries and other defects in the films. The defect scattering was analysed using the phonon confinement model. These results were compared with results obtained from X-ray diffraction powder patterns and high-resolution transmission electron microscopy.

Raman Scattering and X-Ray Diffraction Studies of Gallium Nitride Films Grown on (100) Gallium Arsenide

1994 ◽  
Vol 339 ◽  
Author(s):  
S. W. Brown ◽  
S. C. Rand ◽  
C.-H. Hong ◽  
D. Pavlidis
Keyword(s):  
Gallium Arsenide ◽  
Gallium Nitride ◽  
Raman Scattering ◽  
Raman Spectra ◽  
Phonon Mode ◽  
X Ray Diffraction ◽  
Phonon Modes ◽  
X Ray ◽  
Different Temperatures ◽  
Cubic Gan

ABSTRACTRaman spectroscopy and x-ray diffraction are used to characterize Gallium Nitride (GaN) films grown on (100) Gallium Arsenide (GaAs) substrates. Reflection X-ray diffraction data from (200) planes of GaAs and cubic GaN are presented. The linewidth of the cubic GaN diffraction peak is shown to be a strong function of the growth temperature. Raman spectra are presented for a series of samples grown at different temperatures. Raman scattering is characterized by strong peaks at 560 cm-1 and at 736 cm-1, corresponding to TO and LO phonon modes of cubic GaN, respectively. An additional, unexplained feature at 768 cm-1 is clearly observed in Raman spectra of c-GaN samples grown at lower temperatures. The polarization dependence of the intensity of the GaN LO phonon mode is presented and compared with the GaAs LO phonon mode to establish the relative orientation of the c-GaN epitaxy on GaAs.

Texture measurements in Al2O3 using BEKP

1994 ◽  
Vol 52 ◽  
pp. 608-609
Author(s):  
M. D. Vaudin ◽  
J. P. Cline
Keyword(s):  
Neutron Diffraction ◽  
Rapid Method ◽  
Crystallographic Orientation ◽  
Specimen Surface ◽  
X Ray Diffraction ◽  
Anisotropic Crystal ◽  
X Ray ◽  
Verification Method ◽  
Crystal Properties ◽  
Backscattered Electron

The study of preferred crystallographic orientation (texture) in ceramics is assuming greater importance as their anisotropic crystal properties are being used to advantage in an increasing number of applications. The quantification of texture by a reliable and rapid method is required. Analysis of backscattered electron Kikuchi patterns (BEKPs) can be used to provide the crystallographic orientation of as many grains as time and resources allow. The technique is relatively slow, particularly for noncubic materials, but the data are more accurate than any comparable technique when a sufficient number of grains are analyzed. Thus, BEKP is well-suited as a verification method for data obtained in faster ways, such as x-ray or neutron diffraction. We have compared texture data obtained using BEKP, x-ray diffraction and neutron diffraction. Alumina specimens displaying differing levels of axisymmetric (0001) texture normal to the specimen surface were investigated.BEKP patterns were obtained from about a hundred grains selected at random in each specimen.

scholarly journals Exploring the fundamental effects of deposition time on the microstructure of graphene nanoflakes by Raman scattering and X-ray diffraction

CrystEngComm ◽  
2011 ◽  
Vol 13 (1) ◽  
pp. 312-318 ◽  
Author(s):  
Navneet Soin ◽  
Susanta Sinha Roy ◽  
Christopher O'Kane ◽  
James A. D. McLaughlin ◽  
Teck H. Lim ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Deposition Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Nanoflakes

AIN/GaN and AIGaN/GaN Heterostructures Grown by HVPE on SiC Substrates

1997 ◽  
Vol 482 ◽  
Author(s):  
Yu. V. Melnik ◽  
A. E. Nikolaev ◽  
S. I. Stepanov ◽  
A. S. Zubrilov ◽  
I. P. Nikitina ◽  
...  
Keyword(s):  
Growth Rate ◽  
Electron Beam ◽  
Vapor Phase ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Hydride Vapor Phase Epitaxy ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
X Ray ◽  
Micro Analysis

AbstractGaN, AIN and AIGaN layers were grown by hydride vapor phase epitaxy. 6H-SiC wafers were used as substrates. Properties of AIN/GaN and AIGaN/GaN structures were investigated. AIGaN growth rate was about 1 μm/min. The thickness of the AIGaN layers ranged from 0.5 to 5 μm. The AIN concentration in AIGaN layers was varied from 9 to 67 mol. %. Samples were characterised by electron beam micro analysis, Auger electron spectroscopy, X-ray diffraction and cathodoluminescence.Electrical measurements performed on AIGaN/GaN/SiC samples indicated that undoped AIGaN layers are conducting at least up to 50 mol. % of AIN.

scholarly journals Evidence of a symmetric disordered ice above ~62 GPa from Raman scattering and X-ray diffraction investigations

1996 ◽  
Vol 52 (a1) ◽  
pp. C535-C535
Author(s):  
E. Wolanin ◽  
Ph. Pruzan ◽  
M. Gauthier ◽  
J. C. Chervin ◽  
B. Canny ◽  
...  
Keyword(s):  
Raman Scattering ◽  
X Ray Diffraction ◽  
X Ray
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