New Pathways to Heteroepitaxial GaN by Inorganic CVD Synthesis and Characterization of Related Ga-C-N Novel Systems

1996 ◽  
Vol 449 ◽  
Author(s):  
J. Kouvetakis ◽  
M. O’Keeffe ◽  
Louis Brouseau ◽  
J. McMurran ◽  
Darrick Williams ◽  
...  

ABSTRACTWe describe the development of a new deposition method for thin oriented films of GaN on basal plane sapphire using an exclusively inorganic single-source precursor free of carbon and hydrogen, Cl2GaN3. The films have been characterized by Rutherford backscattering spectroscopy (RBS) and cross sectional transmission electron microscopy (TEM) for composition morphology and structure. RBS analysis confirmed stoichiometric GaN and TEM observations of the highly conformal films revealed heteroepitaxial columnar growth of crystalline wurrtzite material on sapphire. Auger and RBS oxygen and carbon resonance profiles indicated that the films were pure and highly homogeneous. We also report the reactions of Cl2GaN3 with organometallic nitriles to yield a crystalline, novel gallium carbon nitride of composition GaC3N3. Quantitative X-ray powder diffraction has been used to refine the cubic structure of this material which consists of Ga atoms octahedrally surrounded by on the average three C and three N atoms. The structurally analogous LiGaC4N4 phase has also been prepared and characterized.

NANO ◽  
2015 ◽  
Vol 10 (05) ◽  
pp. 1550071 ◽  
Author(s):  
Maoquan Xue ◽  
Changsheng Li

In this paper, regularly shaped AlF 3 particles with cubic structure were successfully synthesized via a solvothermal route. The as-prepared products were characterized by X-ray powder diffraction (XRD), energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The experimental results indicated that reaction temperature and time have significant effects on the morphology of the as-prepared products. A possible formation process has also been investigated on the basis of a series of XRD and SEM studies of the product obtained at different conditions. This well-controlled synthesis approach may be extended to fabricate other metal fluoride materials.


1997 ◽  
Vol 482 ◽  
Author(s):  
S. A. Ustin ◽  
W. Ho

AbstractGaN films have been grown atop SiC intermediate layers on Si(001) and Si(111) substrates using supersonic jet epitaxy (SJE). GaN growth temperatures ranged between 600 °C and 775 °C. Methylsilane (H3SiCH3) was used as the single source precursor for SiC growth and triethylgallium (TEG) and ammonia (NH 3) were the sources for GaN epitaxy. The GaN growth rate was found to depend strongly on substrate orientation, growth temperature, and flux. Structural characterization of the films was done by transmission electron diffraction (TED) and x-ray diffraction (XRD). Growth of GaN on SiC(002) produces a cubic or mixed phase of cubic and wurtzite depending on growth conditions. Growth on SiC(111) produces predominantly wurtzite GaN(0002). Minimum rocking curve widths for GaN(0002) on SiC/Si(111) and GaN(002) on SiC/Si(001) are 0.6° and 1.5°, respectively. Cross Sectional Transmission Electron Microscopy (XTEM) was also performed.


2008 ◽  
Vol 368-372 ◽  
pp. 1130-1132
Author(s):  
Hong Zhi Wang ◽  
Qi Zhang ◽  
Yun Xin Gu ◽  
Yao Gang Li ◽  
Mei Fang Zhu

Ti0.6Cr0.4OxNy bimetallic metal oxynitride nano powder was synthesized by ammonolysis of the nanosized Cr2O3/TiO2 composite powder with n(Ti):n(Cr)=6:4 at 800oC for 8 h. The precursor and the resulting oxynitride were characterized by Auger electron spectroscope (AES), X-ray diffraction analysis (XRD), electron probe microanalysis (EPMA), transmission electron microscopy (TEM), and BET surface area techniques. The result indicated that the precursor was homogenous mixture of Cr2O3 and TiO2 with high BET surface area. The as-synthesized oxynitride powder contains only Ti0.6Cr0.4OxNy with cubic structure. The BET surface area of the oxynitride powder is 37.42 m2/g and the particle size is in the range of 20~30 nm.


2011 ◽  
Vol 194-196 ◽  
pp. 781-784
Author(s):  
Fa Mei Feng ◽  
Jia Qing Xie ◽  
Li Ke Zou ◽  
Bin Xie

Well-dispersed CeO2 nanoparticles were successfully prepared in a simple system composed of sodium bis (2-ethylhexyl) sulfosuccinate (AOT)- octane-water (W/O) microemulsion in this paper. The morphology and microstructure of the products were characterized by the laser particle size analyzer, Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometer (XRD), differential scanning calorimeter (DSC) and transmission electron microscope (TEM). It was found that the CeO2nanoparticles obtained from this method have well-proportioned size distributions; the surfactant (AOT) molecule was adsorbed on the surface of CeO2nanoparticles precursor, which is favorable for the dispersion of CeO2nanoparticles; the CeO2nanoparticles calcined was a crystal of the cubic structure. In addition, the mechanism on the formation of the CeO2nanoparticles was also proposed in this paper.


1994 ◽  
Vol 354 ◽  
Author(s):  
C. Uslu ◽  
B. Park ◽  
D. B. Poker

AbstractA metastable C-Si-N compound has been synthesized by high dose N+ implantation into polycrystalline /8-SiC (cubic phase). The thin films formed upon 100 keV implantations were characterized with respect to various ion doses and target temperatures. X-ray diffraction with a position-sensitive detector and cross-sectional transmission electron microscopy revealed that the as-implanted surfaces contained ∼0.15 jttm thick continuously-buried amorphous layers. Rutherford backscattering spectroscopy showed that the peak concentration of nitrogen saturated up to approximately 54 at. % with increasing doses, suggesting a new phase formation.


1995 ◽  
Vol 10 (10) ◽  
pp. 2401-2403 ◽  
Author(s):  
Q.X. Jia ◽  
S.G. Song ◽  
S.R. Foltyn ◽  
X.D. Wu

Highly conductive metal-oxide RuO2 thin films have been successfully grown on yttria-stabilized zirconia (YSZ) substrates by pulsed laser deposition. Epitaxial growth of RuO2 thin films on YSZ and the atomically sharp interface between the RuO2 and the YSZ substrate are clearly evident from cross-sectional transmission electron microscopy. A diagonal-type epitaxy of RuO2 on YSZ is confirmed from x-ray diffraction measurements. The crystalline RuO2 thin films, deposited at temperatures in the range of 500 °C to 700 °C, have a room-temperature resistivity of 35 ± 2 μω-cm, and the residual resistance ratio (R300 k/R4.2 k) is around 5 for the crystalline RuO2 thin films.


1991 ◽  
Vol 220 ◽  
Author(s):  
P. M. Adams ◽  
R. C. Bowman ◽  
V. Arbet-Engols ◽  
K. L. Wang ◽  
C. C. Ahn

ABSTRACTP-I-N diodes whose intrinsic region consists of strained layer superlattices (SLS), separated by 40 nm Si spacers, have been grown by MBE on Si substrates with <100>, <110>, and <111> orientations. These structures have been characterized by x-ray diffraction (XRD) and cross-sectional transmission electron microscopy (XTEM). The dual periodicities in these structures produced unique XRD effects and the quality was highly dependent on substrate orientation. The <100> sample was in general free of defects, whereas the <110> and <111> specimens contained significant numbers of twins and dislocations.


1993 ◽  
Vol 298 ◽  
Author(s):  
Michael Eichler ◽  
Marita Weidner ◽  
Thomas Morgenstern

AbstractThe range of composition (x) is one of the parameters we often have to measure if Si1-xGex layers are generated by chemical vapour deposition (CVD). It is important in this case, in which way the optical properties of Si1-xGex layers depend on the range of composition. We are interested in using multi-wavelength ellipsometry as a technique for rapid, nondestructive characterization of these samples, without large preparations, especially for series of measurements (2D profiles or wafer-lots). The number of unknown parameters and the multiple solutions are reduced by using several wavelengths during the measurement. The calculation is prepared by the help of parameter-correlation based on results of spectroscopical ellipsometry. To examine the results, thickness and composition were controlled for selected samples by cross-sectional transmission electron microscopy (XTEM) and X-ray double crystal diffractometry (DCD).


1995 ◽  
Vol 379 ◽  
Author(s):  
H.P. Lee ◽  
F.J. Szalkowski ◽  
X. Zeng ◽  
J. Wolfenstine ◽  
J. W. Ager

ABSTRACTLateral compositional graded (GaAs)1-x(Si2)x alloys were deposited on GaAs substrates in a III-V molecular beam epitaxy (MBE) chamber equipped with a electron-beam Si evaporation source. Single crystal GaAs-Si alloys were formed when the deposition temperature was 600°C or higher. The alloys were characterized by Energy Dispersive X-ray Spectroscopy (EDS), Raman scattering measurement and cross-sectional Transmission Electron Microscopy (XTEM). Dislocation-free (GaAs)1-x(Si2)x films of up to x = 0.07 were deposited. For alloys with x between 0.15 < < 0.25, the morphology deteriorates and a high density of stacking faults and micro-twins were observed.


1996 ◽  
Vol 426 ◽  
Author(s):  
T. Wada ◽  
Y. Hashimoto ◽  
K. Kusao ◽  
N. Kohara ◽  
T. Negami ◽  
...  

AbstractCu-rich Cu(In, Ga)Se2 (CIGS) films were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive x-ray fluorescence spectroscopy (EDX) and x-ray photoelectron spectroscopy (XPS). The Cu-rich CIGS film were treated in KCN and NH3 solutions. In the as-deposited Cu-rich CIGS film, the cation ratio of Cu/(In+Ga) at the surface exceeded the bulk value. Cross-sectional TEM of the KCN-treated film suggested that Cu2-xSe existed both at the grain boundaries and on the grains near the surface of the Cu-rich CIGS film. The Cu2-xSe was completely removed by the treatment in the KCN solution and was removed only at the front surface by treatment in the NH3 solution.


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