Study of Depth-Dependent Tetragonal Distortion of GaN Epilayer with Tri-Layer AlGaN Interlayer Growth on Si(111)

2011 ◽  
Vol 413 ◽  
pp. 11-17 ◽  
Author(s):  
Bin Feng Ding ◽  
Yong Quan Chai
Keyword(s):  
Chemical Vapor ◽  
Crystal Quality ◽  
Tetragonal Distortion ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Near Surface ◽  
X Ray ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

A GaN epilayer with tri-layer AlGaN interlayer grown on Si (111) by metal-organic chemical vapor deposition (MOCVD) method was discussed by synchrotron radiation x-ray diffraction (SRXRD) and Rutherford backscattering (RBS)/C. The crystal quality of the epilayer is very good with a χmin=2.1%. According to the results of the θ-2θ scan of GaN(0002) and GaN(1122), the epilayer elastic strains in perpendicular and parallel directions were calculated respectively to be-0.019% and 0.063%. By the angular scan using RBS/C around a symmetric [0001] axis and an asymmetric [1213] axis in the (1010) plane of the GaN layer, the tetragonal distortion (eT ) were determined to be 0.09%. This result coincides with that from SRXRD perfectly. The strain decreases gradually towards the near-surface layer, which will avoid the film cracks efficiently and improve the crystal quality of the GaN epilayer remarkably.

X-ray Diffraction Study of InGaN/GaN Superlattice Implanted with Eu3+ Ions

2009 ◽  
Vol 1202 ◽  
Author(s):  
Mohammad Ahmad Ebdah ◽  
Martin E. Kordesch ◽  
Andre Anders ◽  
Wojciech M. Jadwisienczak
Keyword(s):  
Chemical Vapor ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Gradual Improvement ◽  
X Ray ◽  
Different Temperatures ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Ion Implanted

AbstractIn this work, europium implanted InGaN/GaN SL with a fixed well/barrier thickness ratio grown by metal-organic chemical-vapor deposition (MOCVD) on GaN/(0001) sapphire substrate were investigated. The as-grown and Eu ion implanted InGaN/GaN SLs were annealed at different temperatures ranging from 600°C to 950°C in nitrogen ambient. The quality of the SL interfaces in undoped and implanted structures has been investigated by X-ray diffraction (XRD) at room temperature. The characteristic satellite peaks of SLs were measured for the (0002) reflection up to the second order in the symmetric Bragg geometry. The XRD simulation spectrum of the as-grown SL agrees well with the experimental results. The simulation results show x=0.06 atomic percent the InGaN well sub-layers, with thicknesses of 2.4 and 3.3 nm for single InGaN well and GaN barrier, respectively. It was observed that annealing of the undoped SL does not significantly affect the interfacial quality of the superstructure, whereas, the Eu ion implanted InGaN/GaN SL undergo partial induced degradation. Annealing the implanted SLs shows a gradual improvement of the multilayer periodicity and a reduction of the induced degradation with increasing the annealing temperature as indicated by the XRD spectra.

MOCVD of SnSx thin films for solar cell application

2015 ◽  
Vol 1738 ◽  
Author(s):  
Andrew J. Clayton ◽  
Stuart J. C. Irvine ◽  
Vincent Barrioz ◽  
Alessia Masciullo
Keyword(s):  
Chemical Vapor ◽  
Organic Chemical ◽  
Sulfur Source ◽  
Tin Sulfide ◽  
X Ray Diffraction ◽  
Phase Growth ◽  
Solar Cell Application ◽  
X Ray ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

ABSTRACTAn inline metal organic chemical vapor deposition system was used to deposit tin sulfide at temperatures >500 °C. Tetramethyltin was used as the tin source and diethyldisulfide as the sulfur source. An overhead injector configuration was used delivering both precursors directly over the substrate. The tin and sulfur precursors were premixed before injection to improve chemical reaction in the gas phase. Growth temperatures 500 – 540 °C were employed producing films with approximate 1:1 stoichiometry of Sn and S detected by energy dispersive x-ray spectroscopy. X-ray diffraction showed there to be mixed phases with Sn2S3 present with SnS.

Effect of Graded AlxGa1-xN Interlayer Buffer on the Strain of GaN Grown on Si (111) Using MOCVD Method

2008 ◽  
Vol 1068 ◽  
Author(s):  
KungLiang Lin ◽  
Edward-Yi Chang ◽  
Tingkai Li ◽  
Wei-Ching Huang ◽  
Yu-Lin Hsiao ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Buffer Layers ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray ◽  
Metal Organic ◽  
Proper Design ◽  
Organic Chemical Vapor Deposition ◽  
Gan Film

ABSTRACTGaN film grown on Si substrate with AlN/AlxGa1−xN buffer is studied by low pressure metal organic chemical vapor deposition (MOCVD) method. The AlxGa1−xN film with Al composition varying from 0∼ 0.66 was used. The correlation of the Al composition in the AlxGa1−xN film with the stress of the GaN film grown was studied using high resolution X-ray diffraction including symmetrical and asymmetrical ω/2θscans and reciprocal space maps. It is found that with proper design of the Al composition in the AlxGa1−xN buffer layer, crack-free GaN films can be successfully grown on Si (111) substrates using AlN and AlxGa1−xN buffer layers.

Effects of Cu/Ba Ratio in Precursor on MOCVD-Deposited YBa2Cu3O7-x Films on YYC Buffered Ni-W Alloy Tape

2014 ◽  
Vol 1082 ◽  
pp. 95-99
Author(s):  
Fei Zhang ◽  
Jie Xiong ◽  
Rui Peng Zhao ◽  
Yan Xue ◽  
Bo Wan Tao
Keyword(s):  
Vapor Deposition ◽  
Ybco Film ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Ybco Films ◽  
X Ray ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Alloy Tape

To study the effects of Cu/Ba ratio of precursor on YBa2Cu3O7-x (YBCO) film, we have employed the technique of metal-organic chemical vapor deposition to prepare 500 nm thick YBCO films on CeO2/YSZ/Y2O3 (YYC) buffered Ni-W alloy tapes at series of Cu/Ba ratios of precursor. The analysis obtained from X-ray diffraction and scanning electron microscope revealed that the YBCO films crystallized better and became more continuous and denser as Cu/Ba ratio increased from 0.81 to 1.00, yielding that the critical current density (Jc) of YBCO films at 77K and 0T rose from 1.0 MA/cm2 to 1.4 MA/cm2. Moreover, the energy dispersive spectroscopy indicated that the increase in Cu/Ba ratio of precursor made the Cu/Ba ratio of the YBCO film matrix closer to the theoretical value of 1.5. However, for the Cu/Ba ratio of precursor in the range of 1.00~1.21, the crystallization and texture deteriorated severely and many unexpected precipitates of Ba-Cu-O and Cu-O arose, resulting in the dramatic drop of Jc from 1.4 MA/cm2 to 0.1 MA/cm2.

Enhanced Optical Emission from GaN Film Grown on Composite Intermediate Layers

1999 ◽  
Vol 572 ◽  
Author(s):  
Xiong Zhang ◽  
Soo-Jin Chua ◽  
Peng Li ◽  
Kok-Boon Chong
Keyword(s):  
Silicon Layer ◽  
Chemical Vapor ◽  
Optical Emission ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Intermediate Layers ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Gan Film

ABSTRACTGaN films have been grown on silicon-(001) substrate with specially designed composite intermediate layers consisting of an ultra-thin amorphous silicon layer and a GaN/AlxGa1−xN (x=0.2) multilayered buffer by metal-organic chemical vapor deposition and characterized by photoluminescence and x-ray diffraction spectroscopy. It was found that the GaN films grown on the composite intermediate layers gave comparable or slightly stronger optical emission than those grown on sapphire substrate under identical reactor configuration. Moreover, the full width at half maximum for the GaN band-edge-related emission is 40 meV at room temperature. This fact indicates that, by using the proposed composite intermediate layers, the crystalline quality of GaN-based nitride grown on a silicon substrate can be significantly improved.

scholarly journals MOCVD of Very thin Films of Lead Lanthanum Titanate

1995 ◽  
Vol 415 ◽  
Author(s):  
David B. Beach ◽  
Catherine E. Vallet
Keyword(s):  
Perovskite Phase ◽  
Chemical Vapor ◽  
Precursor Solution ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grain Sizes ◽  
Lanthanum Titanate ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

ABSTRACTFilms of lead lanthanum titanate were deposited using metal-organic chemical vapor deposition (MOCVD) at temperatures between 500 and 550°C in a hot-wall reactor. The precursors used were Pb(THD)2, La(THD)3, and Ti(THD)2(I-OPr)2where THD = 2,2,6,6-tetramethyl-3,5-heptanedionate, O2C11H19, and I-OPr = isopropoxide, OC3H7. The three precursors were delivered to the reactor using a single solution containing all three precursors dissolved in tetraglyme and the precursor solution was volatilized at 225°C. Films were deposited on Si and Si/Ti/Pt substrates, and characterized using Rutherford Backscattering Spectroscopy (RBS) and X-ray diffraction(XRD). Films deposited at 550°C had a composition which was close to that of the precursor solution while films deposited at 500°C were deficient in lanthanum. Even at 500°C, the desired perovskite phase is readily observed by XRD. Subsequent rapid thermal processing of the film deposited at 500°C showed an increase in the intensity of the X-ray lines, but did not change the width of these lines, implying that grain sizes had remained unchanged.

The Growth and Optimization of InPSb/InGaAs/InAsSb Strained-Layer Superlattice Emitters by Metal Organic Chemical Vapor Deposition

1995 ◽  
Vol 379 ◽  
Author(s):  
R. M. Biefeld ◽  
S. R. Kurtz
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strained Layer ◽  
Metal Organic ◽  
Interface Layers ◽  
Organic Chemical Vapor Deposition

ABSTRACTWe have prepared InAsSb/InGaAs strained-layer superlattices (SLS's) and InPSb confinement layers using metal-organic chemical vapor deposition (MOCVD) for use as infrared emitters. X-ray diffraction was used to determine lattice matching as well as composition and structure of the SLS's. Photoluminescence linewidth and intensity were used as a measure of the quality of the structures. Typical FWHM were less than 10 meV. The presence of interface layers were indicated by broadened x-ray diffraction peaks for samples grown under non-optimized conditions. Two types of interfacial layers apparently due to a difference in composition at the interfaces were observed with transmission electron microscopy (TEM). The width of the x-ray peaks can be explained by a variation of the interfacial layer thicknesses. Optimized growth resulted in SLS's with narrow x-ray peaks and high radiative efficiency. Room temperature LEDs operating between 4-5 μm have been prepared.

Light Power Enhancement of Violet LEDs Using AlGaN-Based Epitaxial Structure

2013 ◽  
Vol 331 ◽  
pp. 572-577 ◽  
Author(s):  
Jin Shun Yue ◽  
Ying Gao ◽  
Guo Hua Zhang ◽  
Yi Liu
Keyword(s):  
Chemical Vapor ◽  
Integrated System ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Light Power ◽  
Rocking Curve ◽  
X Ray ◽  
Power Enhancement ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

The growths of AlN and AlGaN materials were carried out in a home-built metal organic chemical vapor deposition (MOCVD) system. The AlN template was characterized by X-ray diffraction (XRD) and it showed the full width at half magnitude (FWHM) of the x-ray (002) scan rocking curve was only 28 arc seconds, while the FWHM of (102) plane was 252 arc seconds. The results suggested a high quality epitaxial material was obtained. Subsequently, an AlGaN-based violet LED was designed on this template by using AlGaN material as the base. The Al composition of electronic blocking layer (EBL) was optimized. By a quick on-wafer electroluminescence (EL) test, it was demonstrated that the output light intensity of the new structure was at least 15% stronger in comparison to that of the traditional GaN-based violet LED. Finally, fully packaged LEDs were fabricated and the luminous power of the new structure was measured by Spherical integrated system. It was confirmed that a 43% increase of the output power can be obtained.

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