DEPTH-DEPENDENT TETRAGONAL DISTORTION STUDY OF AlGaN EPILAYER THIN FILM USING RBS AND CHANNELING TECHNIQUE

An epilayer of wide-band gap Al x Ga 1-x N was grown on sapphire by metal organic chemical vapor deposition (MOCVD) method with a GaN buffer layer of thickness slightly greater than 1 μm. Average composition of Al in the AlGaN layer is determined by Rutherford backscattering spectroscopy (RBS). Simulation of the random spectra reveals that the AlGaN layer has a composition of Al 0.05 Ga 0.95 N and a thickness of 200 nm. Low ratio of channeling and random spectra yields suggests good crystalline quality of ternary AlGaN epilayer. Tetragonal distortion (eT) caused by elastic strain in AlGaN is measured from channeling angular scans taken around an off-normal [Formula: see text] axis in the [Formula: see text] plane of the AlGaN layer. The resulting AlGaN is identified to be showing compressive strain at the interfacial layer and the magnitude of the stress reduces towards the near-surface layer. It can be expected from the results that a 550 nm thick, epitaxially grown, AlGaN layer on sapphire can be relaxed completely (eT = 0).

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Metal Organic Chemical Vapor Deposition of nickel oxide thin films for wide band gap device technology

Thin Solid Films ◽

10.1016/j.tsf.2014.04.012 ◽

2014 ◽

Vol 563 ◽

pp. 50-55 ◽

Cited By ~ 20

Author(s):

Raffaella Lo Nigro ◽

Sergio Battiato ◽

Giuseppe Greco ◽

Patrick Fiorenza ◽

Fabrizio Roccaforte ◽

...

Keyword(s):

Thin Films ◽

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Chemical Vapor ◽

Wide Band ◽

Organic Chemical ◽

Wide Band Gap ◽

Metal Organic ◽

Organic Chemical Vapor Deposition ◽

Device Technology

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.413.11 ◽

2011 ◽

Vol 413 ◽

pp. 11-17 ◽

Cited By ~ 1

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.

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Hexagonal phase-pure wide band gap ε-Ga2O3 films grown on 6H-SiC substrates by metal organic chemical vapor deposition

Applied Physics Letters ◽

10.1063/1.4950867 ◽

2016 ◽

Vol 108 (20) ◽

pp. 202103 ◽

Cited By ~ 63

Author(s):

Xiaochuan Xia ◽

Yuanpeng Chen ◽

Qiuju Feng ◽

Hongwei Liang ◽

Pengcheng Tao ◽

...

Keyword(s):

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Hexagonal Phase ◽

Chemical Vapor ◽

Wide Band ◽

Organic Chemical ◽

Wide Band Gap ◽

Phase Pure ◽

Metal Organic ◽

Organic Chemical Vapor Deposition

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Characterization of Gan/Sapphire Interface and the Buffer Layer by TEM/AFM

Microscopy and Microanalysis ◽

10.1017/s1431927600027720 ◽

2001 ◽

Vol 7 (S2) ◽

pp. 330-331

Author(s):

B. Shea ◽

Q. Sun-Paduano ◽

D. F. Bliss ◽

M. C. Callahan ◽

C. Sung

Keyword(s):

Buffer Layer ◽

Gas Flow ◽

Chemical Vapor ◽

Wide Band ◽

Buffer Layers ◽

Organic Chemical ◽

Wide Band Gap ◽

Tem Analysis ◽

Flow Rates ◽

Device Applications

Interest in wide band gap III-V nitride semiconductor devices is increasing for optoelectronic and microelectronic device applications. to ensure the highest quality, TEM analysis can characterize the substrate and buffer layer interface. Measurements taken by TEM reveal the density of dislocations/cm2 and the orientation of Burger's vectors. This information allows for changes to be made in deposition rates, temperatures, gas flow rates, and other parameters during the processing.The GaN/sapphire samples grown at AFRL were produced in two consecutive steps, first to provide a thin buffer layer, and the other to grow a lum thick epitaxial film. Both growth steps were prepared using metallic organic chemical vapor deposition (MOCVD) in a vertical reactor. Buffer layers were prepared using a range of temperatures from 525 to 535°C and with a range of flow rates and pressures in order to optimize the nucleation conditions for the epitaxial films.

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High Hole Concentration and Diffusion Suppression of Heavily Mg-Doped p-GaN for Application in Enhanced-Mode GaN HEMT

Nanomaterials ◽

10.3390/nano11071766 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1766

Author(s):

Jin-Ji Dai ◽

Thi Thu Mai ◽

Ssu-Kuan Wu ◽

Jing-Rong Peng ◽

Cheng-Wei Liu ◽

...

Keyword(s):

Hole Concentration ◽

Compressive Strain ◽

Chemical Vapor ◽

Organic Chemical ◽

Activation Rate ◽

Activation Efficiency ◽

High Hole Concentration ◽

Metal Organic ◽

Organic Chemical Vapor Deposition ◽

And Diffusion

The effect of Mg doping on the electrical and optical properties of the p-GaN/AlGaN structures on a Si substrate grown by metal organic chemical vapor deposition was investigated. The Hall measurement showed that the activation efficiency of the sample with a 450 sccm Cp2Mg flow rate reached a maximum value of 2.22%. No reversion of the hole concentration was observed due to the existence of stress in the designed sample structures. This is attributed to the higher Mg-to-Ga incorporation rate resulting from the restriction of self-compensation under compressive strain. In addition, by using an AlN interlayer (IL) at the interface of p-GaN/AlGaN, the activation rate can be further improved after the doping concentration reaches saturation, and the diffusion of Mg atoms can also be effectively suppressed. A high hole concentration of about 1.3 × 1018 cm−3 can be achieved in the p-GaN/AlN-IL/AlGaN structure.

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Growth of GaAs/AlGaAs Quantum Dots Using Self-Organized InP Stressors

MRS Proceedings ◽

10.1557/proc-417-129 ◽

1995 ◽

Vol 417 ◽

Cited By ~ 1

Author(s):

M. C. Hanna ◽

Z. H. Lu ◽

A. F. Cahill ◽

M. J. Heben ◽

A. J. Nozik

Keyword(s):

Quantum Dots ◽

Room Temperature ◽

Chemical Vapor ◽

Growth Conditions ◽

Organic Chemical ◽

Near Surface ◽

Self Organized ◽

Metal Organic ◽

Organic Chemical Vapor Deposition

AbstractGaAs quantum dots were formed in a near surface quantum well (QW) by producing lateral confinement with self-organized InP stressors grown in situ by metal organic chemical vapor deposition (MOCVD). We report here the influence of growth conditions on InP island formation on AlGaAs/GaAs single QW structures and also the influence of the QW structure on the optical properties of the GaAs quantum dots. We observe strong photoluminscence up to room temperature from the strain-induced quantum dots with energy redshifts of 70 meV below the QW peak.

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A Study of the Decomposition of GaN during Annealing over a Wide Range of Temperatures

MRS Proceedings ◽

10.1557/proc-743-l11.28 ◽

2002 ◽

Vol 743 ◽

Cited By ~ 1

Author(s):

M. A. Rana ◽

H. W. Choi ◽

M. B. H. Breese ◽

T. Osipowicz ◽

S. J. Chua ◽

...

Keyword(s):

Rutherford Backscattering Spectrometry ◽

Chemical Vapor ◽

Depth Resolution ◽

Surface Region ◽

Organic Chemical ◽

Near Surface ◽

Wide Range ◽

Metal Organic ◽

Amorphous Surface ◽

Nitride Layers

ABSTRACTAnnealing experiments were carried out on gallium nitride layers, which were grown on sapphire through Metal Organic Chemical Vapor Deposition (MOCVD). Rutherford Backscattering Spectrometry (RBS) was performed on as-grown and annealed GaN samples using a 2 MeV proton beam to study the stoichiometric changes in the near-surface region (750 nm) with depth resolution better than 50 nm. No decomposition was measured for temperatures o up to 800 °C. Decomposition in the near-surface region increased rapidly with a further increase o of temperature, resulting in a near-amorphous surface-region for annealing at 1100 °C. The depth profiles of nitrogen and incorporated oxygen in the decomposed GaN are extracted from the nanoscale RBS data for different annealing temperatures. The surface roughness of the GaN layers observed by atomic force microscopy (AFM) is consistent with RBS decomposition measurements. We describe the range of annealing conditions under which negligible decomposition of GaN is observed, which is important in assessing optimal thermal processing conditions of GaN for both conventional and nanoscale optoelectronic devices.

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Structural and electronic properties of defects in semiconductors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100136398 ◽

1995 ◽

Vol 53 ◽

pp. 4-5

Author(s):

J.L. Batstone

Keyword(s):

Semiconductor Device ◽

Chemical Vapor ◽

Misfit Strain ◽

Organic Chemical ◽

Extended Defects ◽

Transmission Electron ◽

Semiconductor Thin Films ◽

Wide Range ◽

Metal Organic ◽

Film Substrate

The development of growth techniques such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy during the last fifteen years has resulted in the growth of high quality epitaxial semiconductor thin films for the semiconductor device industry. The III-V and II-VI semiconductors exhibit a wide range of fundamental band gap energies, enabling the fabrication of sophisticated optoelectronic devices such as lasers and electroluminescent displays. However, the radiative efficiency of such devices is strongly affected by the presence of optically and electrically active defects within the epitaxial layer; thus an understanding of factors influencing the defect densities is required.Extended defects such as dislocations, twins, stacking faults and grain boundaries can occur during epitaxial growth to relieve the misfit strain that builds up. Such defects can nucleate either at surfaces or thin film/substrate interfaces and the growth and nucleation events can be determined by in situ transmission electron microscopy (TEM).

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