High Resolution X-Ray Diffraction Analysis Of Gallium Nitride Grown On Sapphire By Halide Vapor Phase Epitaxy

1996 ◽  
Vol 423 ◽  
Author(s):  
R. J. Matyi ◽  
D. Zhi ◽  
N. R. Perkins ◽  
M. N. Horton ◽  
T. F. Kuech
Keyword(s):  
High Resolution ◽  
Vapor Phase ◽  
Structural Characteristics ◽  
Vapor Phase Epitaxy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sapphire Substrates ◽  
Order Of Magnitude ◽  
Mosaic Distribution ◽  
Peak Widths

AbstractWe report a structural analysis of GaN layers with thicknesses ranging from 10 μm to 250 μm which have been grown on sapphire substrates by halide vapor phase epitaxy (HVPE). The effect of growth rate during HVPE growth has also been examined. The growth was performed using GaCl and ammonia as reactants; growth rates in excess of 90 μm/hr have been achieved. The structural characteristics of these layers have been performed wit'i high resolution x-ray diffractometry. Longitudinal scans parallel to the GaN [0002] direction, transverse scans perpendicular to the [0002], and reciprocal space maps of the total diffracted intensity have been obtained from a variety of GaN layers. The transverse scans typically show broad rocking curves with peak breadths of several hundreds of arcseconds. In contrast, the longitudinal scans (or “θ/2θ scans”) which are sensitive only to strains in the GaN layers (and not their mosaic distributions) showed peak widths that were at least an order of magnitude smaller and in some cases were as narrow as 16 arcseconds. These results suggest that the defect structure of the GaN layers grown by HVPE is dominated by a dislocation-induced mosaic distribution, with the effects of strain in these materials being negligible in comparison.

Characterization of lattice mosaic ofa-plane GaN grown onr-plane sapphire by metalorganic vapor-phase epitaxy

2005 ◽  
Vol 892 ◽  
Author(s):  
Kazuhide Kusakabe ◽  
Shizutoshi Ando ◽  
Kazuhiro Ohkawa
Keyword(s):  
High Resolution ◽  
Vapor Phase ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy ◽  
Morphological Transition ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Sapphire Substrates

AbstractNonpolara-plane GaN films were grown on r-plane sapphire substrates by atmospheric metalorganic vapor-phase epitaxy. The as-grown layers were studied by high-resolution x-ray diffraction. Thea-plane GaN lattice mosaic is orientation dependent as determined by x-ray rocking curve (XRC) measurements. The tilt mosaic measured with the c-axis within the scattering plane (c-mosaic) was greater than the mosaic measured with the m-axis within the scattering plane (m-mosaic). The mosaic along both azimuths decreased and thec-mosaic/m-mosaic ratio was increased with increase of growth temperature from 1050 °C to 1080 °C. The morphological transition was correlated to change in thea-plane GaN tilt mosaic measured by XRC.

High Resolution X-ray Diffraction and X-ray Topography Study of Gan on A12O3

1998 ◽  
Vol 512 ◽  
Author(s):  
J. Chaudhuri ◽  
M. Hooe Ng ◽  
D. D. Koleske ◽  
A. E. Wickenden ◽  
R. L. Henry
Keyword(s):  
Thin Films ◽  
High Resolution ◽  
Dislocation Density ◽  
Carrier Concentration ◽  
Vapor Phase ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy ◽  
X Ray Diffraction ◽  
Reduced Pressure ◽  
X Ray

ABSTRACTHigh resolution x-ray diffraction and x-ray topography study of GaN thin films, grown on sapphire (00.1) substrate by reduced pressure metalorganic vapor phase epitaxy under various conditions, were performed. An attempt was made to correlate the mobility in films with similar carrier concentration with the strain and dislocation density. X-ray topography revealed the defects present in the film.

High-resolution X-ray diffraction analysis of InN films grown by metalorganic vapor phase epitaxy

2007 ◽  
Vol 22 (3) ◽  
pp. 219-222
Author(s):  
W. J. Wang ◽  
K. Sugita ◽  
Y. Nagai ◽  
Y. Houchin ◽  
A. Hashimoto ◽  
...  
Keyword(s):  
High Resolution ◽  
Vapor Phase ◽  
Growth Temperature ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy ◽  
Crystalline Quality ◽  
X Ray Diffraction ◽  
X Ray ◽  
Symmetric Reflection

The growth temperature dependence of the InN film’s crystalline quality is reported. InN films are grown on sapphire substrates from 570 to 650 °C with low-temperature GaN buffers by metalorganic vapor phase epitaxy (MOVPE). The X-ray rocking curves and reciprocal space mappings of the symmetric reflection (0 0 0 2) and asymmetric reflection (1 0 1 2) are measured with high resolution X-ray diffraction. The results indicate that the crystallinity is sensitive to the growth temperature for MOVPE InN. At growth temperature 580 °C, highly crystalline InN film has been obtained, for which the full-width-at-half-maxima of (0 0 0 2) and (1 0 1 2) rocking curves are 24 and 28 arcmin, respectively. The crystalline quality deteriorates drastically when the growth temperature exceeds 600 °C. Combined with the carrier concentration and mobility, the approach to improve the quality of InN film by MOVPE is discussed.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

High Quality AlN Layer Grown on Patterned Sapphire Substrates by Hydride Vapor-Phase Epitaxy: A Route for Cost Efficient AlN Templates for Deep Ultraviolet Light Devices

2021 ◽  
Vol 21 (9) ◽  
pp. 4881-4885
Author(s):  
Seung-Jae Lee ◽  
Seong-Ran Jeon ◽  
Young Ho Song ◽  
Young-Jun Choi ◽  
Hae-Gon Oh ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Threading Dislocation ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Order Of Magnitude ◽  
Cost Efficient ◽  
Patterned Sapphire Substrates

We report the characteristics of AlN epilayers grown directly on cylindrical-patterned sapphire substrates (CPSS) by hydride vapor-phase epitaxy (HVPE). To evaluate the effect of CPSS, we analyzed the threading dislocation densities (TDDs) of AlN films grown simultaneously on CPSS and flat sapphire substrate (FSS) by transmission electron microscopy (TEM). The corresponding TDD is measured to be 5.69 x 108 cm−2 for the AlN sample grown on the CPSS that is almost an order of magnitude lower than the value of 3.43 × 109 cm−2 on the FSS. The CPSS contributes to reduce the TDs originated from the AlN/sapphire interface via bending the TDs by lateral growth during the coalescence process. In addition, the reduction of direct interface area between AlN and sapphire by CPSS reduce the generation of TDs.

High-resolution microbeam x-ray diffractometry applied to InGaAsP/InP layers grown by narrow-stripe selective metal-organic vapor phase epitaxy

2000 ◽  
Vol 77 (9) ◽  
pp. 1286-1288 ◽  
Author(s):  
Shigeru Kimura ◽  
Hidekazu Kimura ◽  
Kenji Kobayashi ◽  
Tomoaki Oohira ◽  
Koich Izumi ◽  
...  
Keyword(s):  
High Resolution ◽  
Vapor Phase ◽  
Vapor Phase Epitaxy ◽  
X Ray ◽  
Organic Vapor ◽  
Metal Organic ◽  
Narrow Stripe
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