The Effect of a GaN Nucleation Layer on GaN Film Properties Grown by Metalorganic Chemical Vapor Deposition

1995 ◽  
Vol 395 ◽  
Author(s):  
W. Van Der Stricht ◽  
I. Moerman ◽  
P. Demeester ◽  
J.A Crawley ◽  
E.J. Thrush ◽  
...  
Keyword(s):  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Rotating Disk ◽  
X Ray Diffraction ◽  
Film Properties ◽  
Double Crystal ◽  
Nucleation Layer ◽  
X Ray ◽  
Sapphire Substrates ◽  
Gan Film

ABSTRACTIn this paper GaN films are examined, which are grown on basal plane (0001) sapphire substrates. Growth is performed in a novel type of vertical rotating disk reactor. Results on the effect of a GaN nucleation layer on the properties of the overgrown GaN epilayer are presented. Characterisation includes surface morphology studies, DC X-ray diffraction and optical characterisation. Best film quality so far has a double crystal X-ray half width of 85 arcsec at approximately 1 μm thickness.

High Resolution X-ray Diffraction of GaN Grown on Sapphire Substrates

1996 ◽  
Vol 449 ◽  
Author(s):  
A. Saxler ◽  
M. A. Capano ◽  
W. C. Mitchel ◽  
P. Kung ◽  
X. Zhang ◽  
...  
Keyword(s):  
Metalorganic Chemical Vapor Deposition ◽  
Reciprocal Lattice ◽  
Chemical Vapor ◽  
Lattice Points ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sapphire Substrates ◽  
Primary Mechanism

ABSTRACTX-ray rocking curves are frequently used to assess the structural quality of GaN thin films. In order to understand the information given by the line shape, we need to know the primary mechanism by which the curves are broadened. The GaN films used in this study were grown by low pressure metalorganic chemical vapor deposition (MOCVD) on (00•1) sapphire substrates. GaN films with both broad and very narrow (open detector linewidth of 40 arcseconds for the (00•2) GaN reflection) rocking curves are examined in this work. Reciprocal space maps of both symmetric and asymmetric reciprocal lattice points are used to determine that the cause of the broadening of GaN rocking curves is a limited in-plane coherence length.

Strain Property Studies of GaN:Mg Films Grown by MOCVD

2005 ◽  
Vol 475-479 ◽  
pp. 1697-1700
Author(s):  
Qian Feng ◽  
Yue Hao
Keyword(s):  
Strain Distribution ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Raman Shift ◽  
X Ray Diffraction ◽  
Strain Property ◽  
X Ray ◽  
Mg Doping ◽  
Sapphire Substrates ◽  
Inhomogeneous Strain

The influence of Mg doping on structural and strain properties in GaN layers grown on sapphire substrates by metalorganic chemical vapor deposition was studied by means of high resolution X-ray diffraction and Raman scattering. The results showed that the disorder of GaN films aggravated and the quality reduced as Mg doping rate increasing. However, according to the theoretic calculation, the compressive stress determined by the Raman shift of the E2 mode was not due to the substitution of Mg atoms for Ga. Furthermore, the SEM measurements indicated that some Mg atoms substituted Ga to become acceptors, while most of them existed as Mg interstitials(Mgi) and aggregated at defects and dislocation, hence a great deal of cracks are introduced during decreasing temperature process for inhomogeneous strain distribution.

AlxGa1-xN-Based Materials and Heterostructures

1996 ◽  
Vol 449 ◽  
Author(s):  
P. Kung ◽  
A. Saxler ◽  
D. Walker ◽  
X. Zhang ◽  
R. Lavado ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Bragg Reflectors ◽  
X Ray Diffraction ◽  
Chemical Vapor Deposition Growth ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Dimensional Electron Gas ◽  
P Type

ABSTRACTWe present the metalorganic chemical vapor deposition growth, n-type and p-type doping and characterization of AlxGa1-xN alloys on sapphire substrates. We report the fabrication of Bragg reflectors and the demonstration of two dimensional electron gas structures using AlxGa1-xN high quality films. We report the structural characterization of the AlxGa1-xN / GaN multilayer structures and superlattices through X-ray diffraction and transmission electron microscopy. A density of screw and mixed threading dislocations as low as 107 cm-2 was estimated in AlxGa1-xN / GaN structures. The realization of AlxGa1-xN based UV photodetectors with tailored cut-off wavelengths from 365 to 200 nm are presented.

Real-Time Composition And Thickness Control Techniques In A Metalorganic Chemical Vapor Deposition Process

1995 ◽  
Vol 406 ◽  
Author(s):  
M. S. Gaffneyt ◽  
C. M. Reavesl ◽  
A. L Holmes ◽  
R. S. Smith ◽  
S. P. DenBaars
Keyword(s):  
Chemical Vapor Deposition ◽  
Real Time ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Normal Operation ◽  
Growth Monitoring ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metalorganic Chemical

AbstractMetalorganic chemical vapor deposition (MOCVD) is a process used to manufacture electronic and optoelectronic devices that has traditionally lacked real-time growth monitoring and control. We have developed control strategies that incorporate monitors as real-time control sensors to improve MOCVD growth. An analog control system with an ultrasonic concentration monitor was used to reject bubbler concentration disturbances which exist under normal operation, during the growth of a four-period GaInAs/InP superlattice. Using X-ray diffraction, it was determined that the normally occurring concentration variations led to a wider GaInAs peak in the uncompensated growths as compared to the compensated growths, indicating that closed loop control improved GaInAs composition regulation. In further analysis of the X-ray diffraction curves, superlattice peaks were used as a measure of high crystalline quality. The compensated curve clearly displayed eight orders of satellite peaks, whereas the uncompensated curve shows little evidence of satellite peaks.

The process and mechanism of the GaN nanoparticles formed by nitridation of β-Ga2O3 crystal

2017 ◽  
Vol 31 (10) ◽  
pp. 1750108 ◽  
Author(s):  
Xiao-Jun Cui ◽  
Liang-Ling Wang
Keyword(s):  
Vapor Deposition ◽  
Surface Defect ◽  
Chemical Vapor ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
Epitaxial Relationship ◽  
X Ray ◽  
Diffraction Peaks ◽  
Relationship Of ◽  
Gan Film

The process of conversion from [Formula: see text]-Ga2O3 single crystal to gallium nitride (GaN) in an atmosphere of NH3 by chemical vapor deposition is investigated. The surface morphology and microstructure of the GaN nanoparticles are observed by scanning electron microscope, which indicates that the growth of GaN is via the Volmer–Weber mechanism. The [Formula: see text]-Ga2O3 is firstly evaporated at high temperature to form the porous layer, followed by the surface-defect induced GaN nucleation formation. The crystalline structure and epitaxial relationship of the GaN nanoparticles are investigated by X-ray diffraction (XRD) via [Formula: see text]–[Formula: see text], showing GaN (0002) and (0004) diffraction peaks in the XRD spectra. It is concluded that the polycrystalline GaN film with hexagonal structure has a strong c-axis preferential orientation.

Analysis Of Sige Fet Device Structures On Silicon-on-sapphire Substrates by X-Ray Diffraction

1998 ◽  
Vol 533 ◽  
Author(s):  
P. M. Mooney ◽  
J. O. Chu ◽  
J. A. Ott ◽  
J. L. Jordan-Sweet ◽  
B. S. Meyerson ◽  
...  
Keyword(s):  
Field Effect Transistors ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Device Fabrication ◽  
Ultra High Vacuum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sapphire Substrates ◽  
Wafer Cleaning ◽  
Device Structures

AbstractSi/Si1-xGex, heterostructures on improved silicon-on-sapphire substrates were grown epitaxially by ultra-high vacuum chemical vapor deposition for application as p-channel field effect transistors. High-resolution triple-axis x-ray diffraction was used to analyze these structures quantitatively and to evaluate the effects of device fabrication processes on them. Out-;diffusion of Ge from the Si1-xGex, quantum well was observed after fabrication as was the change in thickness of the Si cap layer due to wafer cleaning and gate oxidation at 875 °C

scholarly journals Characteristics of MOCVD-Grown High-Quality CdTe Layers on GaAs Substrates

1995 ◽  
Vol 18 (4) ◽  
pp. 247-258
Author(s):  
P. W. Sze ◽  
K. F. Yarn ◽  
Y. H. Wang ◽  
M. P. Houng ◽  
G. L. Chen
Keyword(s):  
Growth Temperature ◽  
Vapor Deposition ◽  
Gaas Substrate ◽  
Concentration Ratio ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Double Crystal ◽  
X Ray ◽  
Gaas Substrates ◽  
Growth System

CdTe epitaxial layers are grown successfully on a (100)-GaAs substrate by metalorganic chemical vapor deposition (MOCVD) using dimethylcadrnium (DMCd) and diethyltelluride (DETe) as alkyl sources. The CdTe epilayers grown between 365°C and 380°C possess the best surface morphology. DETe is used as the controlling species of this growth system. Typical growth rates are varied from 2.51µm/hr to 5.31µm/hr. Low-temperature (12K) photoluminscence (PL) measurements reveal that 380°C is the best growth temperature and the full width at half maximum (FWHM) of the dominated peak is about 1.583eV by the bound-exciton emission of 9.38meV. The double crystal X-ray rocking curves (DCRC) indicate that the FWHM decreases while increasing the epilayer thickness and approaches a stable value about 80 arc sec under the growth rate of 5.2µm/hr, the growth temperature of 380°C and the DETe/DMCd concentration ratio of 1.7. The value of 80 arc sec in FWHM is the smallest one ever reported to date.

Oxidation of Gallium Nitride Epilayers in Dry Oxygen

1999 ◽  
Vol 595 ◽  
Author(s):  
P. Chen ◽  
R. Zhang ◽  
X.F. Xu ◽  
Z.Z. Chen ◽  
Y.G. Zhou ◽  
...  
Keyword(s):  
Diffusion Mechanism ◽  
Chemical Vapor ◽  
Oxide Surface ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sapphire Substrates ◽  
Different Temperatures ◽  
Diffraction Peaks ◽  
And Diffusion

AbstractThe oxidation of GaN epilayers in dry oxygen has been studied. The 1-μm-thick GaN epilayers grown on (0001) sapphire substrates by Rapid-Thermal-Processing/Low Pressure Metalorganic Chemical Vapor Deposition were used in this work. The oxidation of GaN in dry oxygen was performed at various temperatures for different time. The oxide was identified as the monoclinic β-Ga2O3 by a θ-2θ scan X-ray diffraction (XRD). The scanning electron microscope observation shows a rough oxide surface and an expansion of the volume. XRD data also showed that the oxidation of GaN began to occur at 800°C. The GaN diffraction peaks disappeared at 1050°C for 4 h or at 1100°C for 1 h, which indicates that the GaN epilayers has been completely oxidized. From these results, it was found that the oxidation of GaN in dry oxygen was not layer-by-layer and limited by the interfacial reaction and diffusion mechanism at different temperatures.

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