TEM Study of the Morphology Of GaN/SiC (0001) Grown at Various Temperatures by MBE

1999 ◽  
Vol 595 ◽  
Author(s):  
W.L. Sarney ◽  
L. Salamanca-Riba ◽  
V. Ramachandran ◽  
R.M Feenstra ◽  
D.W. Greve
Keyword(s):  
Low Temperatures ◽  
Stacking Faults ◽  
Full Width ◽  
X Ray Diffraction ◽  
High Quality ◽  
Double Crystal ◽  
Tem Analysis ◽  
Rocking Curve ◽  
X Ray ◽  
Substrate Temperatures

AbstractGaN films grown on SiC (0001) by MBE at various substrate temperatures (600° - 750° C) were characterized by RHEED, STM, x-ray diffraction, AFM and TEM. This work focuses on the TEM analysis of the films' features, such as stacking faults and dislocations, which are related to the substrate temperature. There are several basal plane stacking faults in the form of cubic inclusions for samples grown at low temperatures compared to those grown at high temperatures. The dislocation density is greatest for the film grown at 600°C, and it steadily decreases with increasing growth temperatures. Despite the presence of various defects, x-ray analysis shows that the GaN films are of high quality. The double crystal rocking curve full width at half maximum (FWHM) for the GaN (0002) peak is less than 2 arc-minutes for all of the films we measured and it decreases with increasing growth temperature.

scholarly journals TEM Study of the Morphology Of GaN/SiC (0001) Grown at Various Temperatures by MBE

2000 ◽  
Vol 5 (S1) ◽  
pp. 238-244
Author(s):  
W.L. Sarney ◽  
L. Salamanca-Riba ◽  
V. Ramachandran ◽  
R.M Feenstra ◽  
D.W. Greve
Keyword(s):  
Low Temperatures ◽  
Stacking Faults ◽  
Full Width ◽  
X Ray Diffraction ◽  
High Quality ◽  
Double Crystal ◽  
Tem Analysis ◽  
Rocking Curve ◽  
X Ray ◽  
Substrate Temperatures

GaN films grown on SiC (0001) by MBE at various substrate temperatures (600° - 750° C) were characterized by RHEED, STM, x-ray diffraction, AFM and TEM. This work focuses on the TEM analysis of the films’ features, such as stacking faults and dislocations, which are related to the substrate temperature. There are several basal plane stacking faults in the form of cubic inclusions for samples grown at low temperatures compared to those grown at high temperatures. The dislocation density is greatest for the film grown at 600°C, and it steadily decreases with increasing growth temperatures. Despite the presence of various defects, x-ray analysis shows that the GaN films are of high quality. The double crystal rocking curve full width at half maximum (FWHM) for the GaN (0002) peak is less than 2 arc-minutes for all of the films we measured and it decreases with increasing growth temperature.

X-Ray Diffraction Studies of Low Temperature GaAs

1991 ◽  
Vol 241 ◽  
Author(s):  
G. Kowaljki ◽  
M. Leszcjynski ◽  
A. Kurpiewski ◽  
M. Kaminska ◽  
T. Suski ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Lattice Relaxation ◽  
Light Illumination ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Large Lattice ◽  
Low Temperature Gaas ◽  
Substrate Temperatures

ABSTRACTGaAs layers grown by molecular beam epitaxy (MBE) at low substrate temperatures (LT GaAs) were studied in a novel purpose designed X-ray experiment. It combines X-ray double crystal rocking curve measurements with some elements usually found in optical setups like light illumination at liquid nitrogen temperatures applied to transfer EL2 type defects into metastable state. Ability to record such transfers with the X-ray experiment as well as large lattice relaxation accompanying this process is presented.

Hot-mesh Chemical Vapor Deposition for 3C-SiC Growth on Si and SiO2

2005 ◽  
Vol 862 ◽  
Author(s):  
Kanji Yasui ◽  
Jyunpei Eto ◽  
Yuzuru Narita ◽  
Masasuke Takata ◽  
Tadashi Akahane
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
Mesh Structure ◽  
X Ray ◽  
Si Substrates ◽  
Substrate Temperatures ◽  
Sic Films

AbstractThe crystal growth of SiC films on (100) Si and thermally oxidized Si (SiO2/Si) substrates by hot-mesh chemical vapor deposition (HMCVD) using monomethylsilane as a source gas was investigated. A mesh structure of hot tungsten (W) wire was used as a catalyzer. At substrate temperatures above 750°C and at a mesh temperature of 1600°C, 3C-SiC crystal was epitaxially grown on (100) Si substrates. From the X-ray rocking curve spectra of the (311) peak, SiC was also epitaxially grown in the substrate plane. On the basis of the X-ray diffraction (XRD) measurements, on the other hand, the growth of (100)-oriented 3C-SiC films on SiO2/Si substrates was determined to be achieved at substrate temperatures of 750-800°C, while polycrystalline SiC films, at substrate temperatures above 850°C. From the dependence of growth rate on substrate temperature and W-mesh temperature, the growth mechanism of SiC crystal by HMCVD was discussed.

On the problem of overlapping ω scans measured on thin films deposited on monocrystal substrates

1999 ◽  
Vol 32 (4) ◽  
pp. 736-743 ◽  
Author(s):  
D. Machajdík ◽  
A. Pevala ◽  
A. Rosová ◽  
K. Fröhlich ◽  
J. Šouc ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Spectral Characteristics ◽  
Full Width ◽  
X Ray Diffraction ◽  
Resolution Function ◽  
High Quality ◽  
Experimental Procedure ◽  
X Ray ◽  
Crystallographic Planes

CeO2thin films deposited on sapphire monocrystal substrates were used for an experimental study of the nature of extremely narrow overlapped maxima on X-ray diffraction ω scans. Full width at half-maximum (FWHM) values of such maxima typically reached the resolution function of the diffractometer. A comparative study of the influence of various diffractometer set-ups on the spectral characteristics of the X-ray beam in relation to the above-mentioned phenomenon was carried out. A surrounding (λmin− λmax) or (2θmin− 2θmax) of the strong substrate reflection was obtained, where a substrate contribution to an ω scan measured on thin-film reflection can be expected. Two possible origins of the narrow maxima are discussed: (a) a contribution of a part of the X-ray beam having λ ≠ λKαthat diffracts on a set of substrate crystallographic planes parallel to the thin-film crystallographic planes used for the ω-scan measurement; and (b) the presence in part of the thin film of a perfect monocrystal-like quality with practically no mosaicity. The principles of this approach and experimental procedure are reported, and on this basis it is possible to distinguish between the two possible origins of the narrow overlapped maxima. It is shown that under appropriate conditions, an extremely high quality CeO2thin film can be grown. The FWHM value of its ω scan can reach the value of diffractometer instrumental broadening obtained for a perfect monocrystal.

Investigation of the structure and phase transitions of the polymeric inorganic–organic hybrids: [M(Im)4V2O6]∞; M = Mn, Co, Ni, Im = imidazole

2010 ◽  
Vol 67 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Kittipong Chainok ◽  
Kenneth J. Haller ◽  
A. David Rae ◽  
Anthony C. Willis ◽  
Ian D. Williams
Keyword(s):  
Phase Transition ◽  
Low Temperatures ◽  
Stacking Faults ◽  
Local Geometry ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Disordered Phase ◽  
Large Hysteresis ◽  
Close Proximity

The polymeric isomorphous hybrid inorganic–organic vanadium oxide compounds [M(Im)4V2O6]∞, M = Mn, Co, Ni, Im = imidazole, were investigated at various temperatures between 100 and 295 K by single-crystal X-ray diffraction. The crystals all contain two-dimensional polymeric sheets packed perpendicular to c* and are 1:1 disordered in the space group P42/n (Z = 8) at 295 K. The disordered phase is reversibly transformed to an I41/a ordered phase (Z = 32) below 281 K for the Mn compound and below 175 K for the Co compound. Within a localized region of the I41/a phase eight imidazoles are in close proximity and seven of these are hydrogen bonded to framework O atoms. The hydrogen-bond connectivity of six of these ligands is unchanged by the phase transition that allows an inversion of the local geometry using an inversion operator that is a symmetry element of P42/n, but not I41/a. The Mn structure has a well defined phase transition but the Co structure shows a large hysteresis and it was necessary to include stacking faults in the modelling of the Co structure at low temperatures. The Ni structure was shown to be partially twinned, but ordered in the space group P2/n (Z = 8) at 100 K, with two different localized regions each containing four pairs of inversion-related imidazoles, hydrogen bonding to framework O atoms involving eight imidazoles in one region and six imidazoles in the other. Models for the phase transition mechanisms are considered.

High Resolution X-Ray Diffraction Analysis of Piezoelectric LiNbO3 Films.

1995 ◽  
Vol 401 ◽  
Author(s):  
Yoshihiko Shibata ◽  
Naohiro Kuze ◽  
Masahiro Matsui ◽  
Masaki Kanal ◽  
Tomoji Kawai
Keyword(s):  
Laser Ablation ◽  
High Resolution ◽  
The Other ◽  
Full Width ◽  
Half Maximum ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Excimer Laser Ablation ◽  
Sapphire Substrates

AbstractThin LINbO3 films are deposited on (001) sapphire and (001) LiTaO3 substrates by using pulsed excimer-laser ablation. These films are evaluated by high-resolution X-ray diffraction (HRXRD) analysis. Strained LiNbO3 films in which the a-axis is longer and the c-axis is shorter than those of LiNbO3 single crystals are deposited on the sapphire substrates. On the other hand, extremely high-quality LiNbO3 films in which the a-axis of the films is the same as that of substrates are grown on the LiTaO substrates. X-ray rocking curves for the (006) reflection showed very narrow full width at half maximum (FWHM) of 208 arcsec for the films on the sapphire substrates, and 9 arcsec for the films on LiTaO3 substrates.

CdTe Films Grown on InSb Substrates by Organometallic Epitaxy

1986 ◽  
Vol 90 ◽  
Author(s):  
I. B. Bhat ◽  
N. R. Taskar ◽  
J. Ayers ◽  
K. Patel ◽  
S. K. Ghandhi
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Organometallic Vapor Phase Epitaxy ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Cdte Films ◽  
Secondary Ion ◽  
Cdte Growth

ABSTRACTCadmium telluride layers were grown on InSb substrates by organometallic vapor phase epitaxy and examined using secondary ion mass spectrometry (SIMS), photoluminescence (Pb) and double crystal x-ray diffraction (DCD). The substrate temperature and the nature of the surface prior to growth are shown to be the most important parameters which influence the quality of CdTe layers. Growth on diethyltelluride (DETe) stabilized InSb substrates resulted in CdTe growth with a misorientation of about 4 minutes of arc with respect to the substrates. On the other hand, the grown layers followed the orientation of the substrates when a dimethylcadmium (DMCd) stabilized InSb was used. Growth at 350°C resulted in the smallest x-ray rocking curve (DCRC) full width at half maximum (FWHM) of about 20 arc seconds.

High Resolution Digital X-Ray Rocking Curve Topography

1986 ◽  
Vol 30 ◽  
pp. 527-535 ◽  
Author(s):  
T.S. Ananthanarayanan ◽  
W.E. Mayo ◽  
R.G. Rosemeier
Keyword(s):  
Defect Structure ◽  
Semiconductor Device ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Rocking Curve ◽  
Crystalline Materials ◽  
Digital Implementation ◽  
X Ray ◽  
Rapid Characterization ◽  
Non Destructive

AbstractThis study presents a unique and novel enhancement of the double crystal diffractometer which allows topographic mapping of X-ray diffraction rocking curve half widths at about 100-150μm spatial resolution. This technique can be very effectively utilized to map micro-lattice strain fields in crystalline materials. The current focus will be on the application of a recently developed digital implementation for the rapid characterization of defect structure and distribution in various semiconductor materials.Digital Automated Rocking Curve (DARC) topography has been successfully applied for characterizing defect structure in materials such as: GaAs, Si, AlGaAs, HgMnTe, HgCdTe, CdTe, Al, Inconnel, Steels, BaF2 PbS, PbSe, etc. The non-intrusive (non- contact & non-destructive) nature of the DARC technique allows its use in studing several phenomena such as corrosion fatigue, recrystallization, grain growth, etc., in situ. DARC topography has been used for isolating regions of non-uniform dislocation density on various materials. It is envisioned that this highly sophisticated, yet simple to operate, system will improve semiconductor-device yield significantly.The high strain sensitivity of the technique results from combination of the highly monochromated and collimated X-ray probe beani, the State of the art linear position-sensitive detector (LPSD) and the high-precision specimen goniometer.

X-Ray Rocking Curve Analysis of S-Implanted GaAs

1988 ◽  
Vol 126 ◽  
Author(s):  
M. Fatemi ◽  
P.E. Thompson ◽  
J. Chaudhuri ◽  
S. Shah
Keyword(s):  
Thin Film ◽  
Curve Analysis ◽  
Maximum Strain ◽  
Major Peak ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Positive Strain ◽  
Two Peaks

ABSTRACTThe effect of rapid thermal annealing on strain reduction in 1.15 MeV S-implanted GaAs wafers irradiated to a dose of 5 × 1014/cm2 has been studied by double-crystal x-ray diffraction technique. X-ray rocking curves exhibit characteristic thin film fringes between the peak of unstrained GaAs and the major peak of the strained region. The maximum strain, i.e., the separation between the two peaks, as well as the number of minor fringes decreases with increasing RTA temperature, while the relative spacing between the fringes remains constant. At temperatures above 900°C, the main peaks begin to overlap; however, a residual positive strain can be measured for temperatures as high as 1100°C.

{224} Plane X-Ray Diffraction Study of GaAs on Si Wafers Using a Conventional Double Crystal Diffractometer

1987 ◽  
Vol 91 ◽  
Author(s):  
J.W. Lee ◽  
D.K. Bowen ◽  
J.P. Salerno
Keyword(s):  
Incident Angle ◽  
Wafer Surface ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Near Surface ◽  
Rocking Curve ◽  
X Ray ◽  
Gaas On Si ◽  
Plane Diffraction

ABSTRACTIn an effort to evaluate the near surface crystal quality of GaAs on Si wafers, {224} plane diffraction were investigated using a conventional double crystal x-ray diffractometer without any high intensity radiation source. The x-ray incident angle to wafer surface varied from 3.6 to 9.6 degrees for different {224} planes due to the substrate tilt angle of 3 degrees. The GaAs to Si rocking curve intensity ratio increased significantly as the incident angle decreased. For the diffraction with 3.6 degree incident angle, only the GaAs peak was detected from the 3.5 um thick GaAs on Si wafer and the GaAs peak became narrower. These indicates that this conventional x-ray diffraction technique is applicable for the near surface quality evaluation of GaAs on Si wafers.

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