The Composition Pulling Effect in InGaN Growth on the GaN and AlGaN Epitaxial Layers Grown by MOVPE

1996 ◽  
Vol 449 ◽  
Author(s):  
Yasutoshi Kawaguchi ◽  
Masaya Shimizu ◽  
Kazumasa Hiramatsu ◽  
Nobuhiko Sawaki
Keyword(s):  
Mole Fraction ◽  
Vapor Phase ◽  
Growth Stage ◽  
Lattice Mismatch ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Crystalline Quality ◽  
Epitaxial Layers ◽  
Initial Growth ◽  
Initial Growth Stage

ABSTRACTInGaN has been grown on GaN and AlGaN epitaxial layers by metalorganic vapor phase epitaxy (MOVPE) and ‘the composition pulling effect’ at the initial growth stage of InGaN has been studied in relation to the lattice mismatch between InGaN and the bottom epitaxial layers. Crystalline quality of InGaN is good near the interface of InGaN/GaN and the composition of InGaN is close to that of GaN. With increasing growth thickness, the crystalline quality becomes worse and the indium mole fraction is increased. The composition pulling effect becomes stronger with increasing lattice mismatch.

Initial Growth Stage of AlGaN Grown Directly on (0001) 6H-SiC by MOVPE

1996 ◽  
Vol 449 ◽  
Author(s):  
K. Horino ◽  
A. Kuramata ◽  
T. Tanahashi
Keyword(s):  
Surface Morphology ◽  
Vapor Phase ◽  
Growth Process ◽  
Growth Stage ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Initial Growth ◽  
Rich Region ◽  
X Ray ◽  
Edx Analysis ◽  
Initial Growth Stage

ABSTRACTWe investigated the growth process of AlGaN films grown directly on 6H-SiC (0001) substrates by metalorganic vapor phase epitaxy (MOVPE). We focused on the initial growth stage to clarify the mechanism of nitride growth on SiC. From Energy Dispersive X-ray (EDX) analysis we found that an Al-rich region generated naturally at the AlGaN/SiC interface. We also found that Al flux determined the density of grain which generated during the initial growth stage, and this grain density reflected the surface morphology.

scholarly journals Investigation of Factors Influencing the Occurrence of 3C-Inclusions for the Thick Growth of on-Axis C-Face 4H-SiC Epitaxial Layers

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4818
Author(s):  
Keiko Masumoto ◽  
Kazutoshi Kojima ◽  
Hiroshi Yamaguchi
Keyword(s):  
Silicon Carbide ◽  
Epitaxial Layer ◽  
Flow Rate ◽  
Growth Stage ◽  
Epitaxial Layers ◽  
Initial Growth ◽  
Free Standing ◽  
Initial Growth Stage ◽  
Factors Influencing ◽  
Homoepitaxial Layers

In this study, we grew homoepitaxial layers on 3-inch on-axis carbon-face 4H-silicon carbide substrates and attempted to suppress the generation of 3C-inclusions. It was found that the 3C-inclusion density decreased with increasing time spent on reaching an objective flow rate for the precursors. It is suggested that 3C-SiC nucleation occurred on large terraces of the on-axis substrates, which existed before the substrates were covered with spiral hillocks. This nucleation was suppressed owing to the decrease in the degree of supersaturation at the initial growth stage. Moreover, we found that the 3C-inclusions were also generated owing to contamination in the form of graphite products. Furthermore, we succeeded in growing a thick on-axis 4H-SiC homoepitaxial layer on a 3-inch substrate and demonstrating its free-standing epitaxial layer with a thickness of 182 μm and a 3C-inclusion density of 2.0 cm−2.

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.

scholarly journals Investigation of the Heteroepitaxial Process Optimization of Ge Layers on Si (001) by RPCVD

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 928
Author(s):  
Yong Du ◽  
Zhenzhen Kong ◽  
Muhammet Toprak ◽  
Guilei Wang ◽  
Yuanhao Miao ◽  
...  
Keyword(s):  
High Temperature ◽  
Buffer Layer ◽  
Layer Thickness ◽  
Growth Temperature ◽  
Crystalline Quality ◽  
Initial Growth ◽  
Two Dimensional ◽  
High Quality ◽  
Reduced Pressure

This work presents the growth of high-quality Ge epilayers on Si (001) substrates using a reduced pressure chemical vapor deposition (RPCVD) chamber. Based on the initial nucleation, a low temperature high temperature (LT-HT) two-step approach, we systematically investigate the nucleation time and surface topography, influence of a LT-Ge buffer layer thickness, a HT-Ge growth temperature, layer thickness, and high temperature thermal treatment on the morphological and crystalline quality of the Ge epilayers. It is also a unique study in the initial growth of Ge epitaxy; the start point of the experiments includes Stranski–Krastanov mode in which the Ge wet layer is initially formed and later the growth is developed to form nuclides. Afterwards, a two-dimensional Ge layer is formed from the coalescing of the nuclides. The evolution of the strain from the beginning stage of the growth up to the full Ge layer has been investigated. Material characterization results show that Ge epilayer with 400 nm LT-Ge buffer layer features at least the root mean square (RMS) value and it’s threading dislocation density (TDD) decreases by a factor of 2. In view of the 400 nm LT-Ge buffer layer, the 1000 nm Ge epilayer with HT-Ge growth temperature of 650 °C showed the best material quality, which is conducive to the merging of the crystals into a connected structure eventually forming a continuous and two-dimensional film. After increasing the thickness of Ge layer from 900 nm to 2000 nm, Ge surface roughness decreased first and then increased slowly (the RMS value for 1400 nm Ge layer was 0.81 nm). Finally, a high-temperature annealing process was carried out and high-quality Ge layer was obtained (TDD=2.78 × 107 cm−2). In addition, room temperature strong photoluminescence (PL) peak intensity and narrow full width at half maximum (11 meV) spectra further confirm the high crystalline quality of the Ge layer manufactured by this optimized process. This work highlights the inducing, increasing, and relaxing of the strain in the Ge buffer and the signature of the defect formation.

A Tem study of GaN Grown by ELO on (0001) 6H-SiC

1999 ◽  
Vol 595 ◽  
Author(s):  
P. Ruterana ◽  
B. Beaumont ◽  
P. Gibart ◽  
Y. Melnik
Keyword(s):  
Basal Plane ◽  
Lattice Mismatch ◽  
Early Stage ◽  
Vapour Phase ◽  
Epitaxial Layers ◽  
Prismatic Plane ◽  
Vapour Phase Epitaxy ◽  
Hexagonal Shape ◽  
To Come

AbstractThe misfit between GaN and 6H-SiC is 3.5% instead of 16% with sapphire, the epitaxial layers have similar densities of defects on both substrates. Moreover, the lattice mismatch between AlN and 6H-SiC is only 1%. Therefore, epitaxial layer overgrowth (ELO) of GaN on AlN/6H-SiC could be a route to further improve the quality of epitaxial layers. AlN has been grown by Halide Vapour Phase Epitaxy (HVPE) on (0001) 6H-SiC, thereafter a dielectric SiO2 mask was deposited and circular openings were made by standard photolithography and reactive ion etching. We have examined GaN layers at an early stage of coalescence in order to identify which dislocations bend and try to understand why. The analysed islands have always the same hexagonal shape, limited by {0110} facets. The a type dislocations are found to fold many times from basal to the prismatic plane, whereas when a+c dislocations bend to the basal plane, they were not seen to come back to a prismatic one.

Sign in / Sign up

Export Citation Format

Share Document