scholarly journals Investigation of AlGaN/GaN Heterostructures Grown on Sputtered AlN Templates with Different Nucleation Layers

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4050 ◽  
Author(s):  
Chuan-Yang Liu ◽  
Ya-Chao Zhang ◽  
Sheng-Rui Xu ◽  
Li Jiang ◽  
Jin-Cheng Zhang ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Layer Growth ◽  
Organic Chemical ◽  
Propagation Mechanism ◽  
Nucleation Layer ◽  
Low Dislocation Density ◽  
Structural And Electrical Properties ◽  
Metal Organic

In this work, a sputtered AlN template is employed to grow high-quality AlGaN/GaN heterostructures, and the effects of AlN nucleation layer growth conditions on the structural and electrical properties of heterostructures are investigated in detail. The optimal growth condition is obtained with composited AlN nucleation layers grown on a sputtered AlN template, resulting in the smooth surface morphology and superior transport properties of the heterostructures. Moreover, high crystal quality GaN material with low dislocation density has been achieved under the optimal condition. The dislocation propagation mechanism, stress relief effect in the GaN grown on sputtered AlN, and metal organic chemical vapor deposition AlN nucleation layers are revealed based on the test results. The results in this work demonstrate the great potential of AlGaN/GaN heterostructures grown on sputtered AlN and composited AlN nucleation layers for microelectronic applications.

A Nucleation Study of GaN Multifunctional Nanostructures

2004 ◽  
Vol 831 ◽  
Author(s):  
Gupta Shalini ◽  
Kang Hun ◽  
Strassburg Martin ◽  
Asghar Ali ◽  
Senawiratne Jayantha ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Mocvd Growth ◽  
Aspect Ratios ◽  
Nucleation Sites ◽  
Wide Range ◽  
Metal Organic ◽  
Multifunctional Nanostructures

ABSTRACTThis paper reports the Metal Organic Chemical Vapor Deposition (MOCVD) growth of GaN nanostructures. The use of MOCVD allows the direct integration of these nanostructures into pre-existing device technology. The formation of GaN nanostructures grown on AlN epitaxial layers were studied as a function of growth temperature, growth rate, V-III ratio and the amount of deposited material. A wide range of temperatures from 800 °C to 1100 °C and V-III ratios from 30 to 3500 were applied to determine the optimal growth conditions for nucleation studies in a modified production reactor. Small GaN nanostructures with lateral dimensions below 50 nm and low aspect ratios were obtained using relatively low temperatures of 815 °C and extreme metal-rich growth conditions. Island densities up to 1010 cm−2 were achieved using silane as an anti-surfactant to increase the available nucleation sites. Manganese has been incorporated into these nanostructures to enhance the multifunctional ferromagnetic properties of GaMnN.

Growth optimization for high quality GaN films grown by metal-organic chemical vapor deposition

2008 ◽  
Vol 1068 ◽  
Author(s):  
Jung Hun Jang ◽  
A M Herrero ◽  
Seungyoung Son ◽  
B Gila ◽  
C Abernathy ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
High Temperature ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Crystalline Quality ◽  
Organic Chemical ◽  
Nucleation Layer ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

ABSTRACTGaN layers were grown on c-plane sapphire substrates by using a conventional two step growth method via metal organic chemical vapor deposition (MOCVD). The effect of different growth conditions used in the deposition of the low temperature nucleation layer and high temperature islands on the crystalline quality of the GaN layers was investigated by high resolution X-ray diffraction (HRXRD) and transmission electron microscopy (TEM). The polar (tilt) and azimuthal (twist) spread were estimated from the full width at half maximum (FWHM) values of the omega rocking curves (¥ø-RCs) recorded from the planes parallel and perpendicular to the sample surface. It was found from the XRD and TEM study that the edge and mixed type threading dislocations are dominant defects so that the relevant figure of merit (FOM) for the crystalline quality should be considered only by the FWHM value of ¥ø-RC of the surface perpendicular plane. The result showed that the mixed- and edge-types dislocations were strongly associated with the growth conditions used in the deposition of the nucleation layer and high temperature islands.

Metal Organic Chemical Vapor Deposition of Zinc Oxide

2005 ◽  
Vol 892 ◽  
Author(s):  
William E. Fenwick ◽  
Vincent T. Woods ◽  
Ming Pan ◽  
Nola Li ◽  
Matthew H. Kane ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Growth Parameters ◽  
Chemical Vapor ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

AbstractThin films of ZnO were grown by metal organic chemical vapor deposition (MOCVD) in a vertical injection rotating disk reactor (RDR) system on sapphire substrates. Kinetics of ZnO growth by MOCVD were studied and an optimal growth window for a RDR tool was determined. Experimental growth conditions were chosen based on calculations of Reynolds Number (Re) and mixed convection parameter in order to select a growth window with stable gas flow and uniform heat transfer. Growth parameters were systemically varied within this window to determine the optimal growth conditions for this MOCVD tool and to study how these parameters affect film growth and quality. Properties of ZnNiO films grown by MOCVD were also studied to determine the effects of Ni incorporation on structural, optical, and magnetic properties.

Surface Morphology of AlN Nucleation Layer Grown on Si by MOCVD

2015 ◽  
Vol 1120-1121 ◽  
pp. 391-395 ◽  
Author(s):  
Shu Fan ◽  
Le Yu ◽  
Xiao Long He ◽  
Ping Han ◽  
Cai Chuan Wu ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Growth Time ◽  
Organic Chemical ◽  
Nucleation Layer ◽  
Coverage Ratio ◽  
3 Dimensional ◽  
Aln Film ◽  
Metal Organic ◽  
Dimensional Growth ◽  
Organic Chemical Vapor Deposition

The AlN nucleation layer (NL) has been deposited on Si (111) substrate by metal-organic chemical vapor deposition (MOCVD). The result indicates that the growth mode of the AlN NL is in the form of 2-dimensional plane and 3-dimensional island. The proportion of 3-dimensional region increases gradually and the 2-dimensional region reduces correspondingly with the increase of growth time. The decrease of the coverage ratio of AlN grains in the 2-dimensional growth region is due to the effect of etching. AlN film with the single crystal orientation has been deposited on the optimized AlN NL.

Microstructural Characterization of GaN Grown on SiC

2019 ◽  
Vol 25 (6) ◽  
pp. 1383-1393
Author(s):  
Sabyasachi Saha ◽  
Deepak Kumar ◽  
Chandan K. Sharma ◽  
Vikash K. Singh ◽  
Samartha Channagiri ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Raman Spectroscopy ◽  
Surface Morphology ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Organic Chemical ◽  
Nucleation Layer ◽  
Transmission Electron ◽  
Vapor Deposition Technique ◽  
Metal Organic

AbstractGaN films have been grown on SiC substrates with an AlN nucleation layer by using a metal organic chemical vapor deposition technique. Micro-cracking of the GaN films has been observed in some of the grown samples. In order to investigate the micro-cracking and microstructure, the samples have been studied using various characterization techniques such as optical microscopy, atomic force microscopy, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy (TEM). The surface morphology of the AlN nucleation layer is related to the stress evolution in subsequent overgrown GaN epilayers. It is determined via TEM evidence that, if the AlN nucleation layer has a rough surface morphology, this leads to tensile stresses in the GaN films, which finally results in cracking. Raman spectroscopy results also suggest this, by showing the existence of considerable tensile residual stress in the AlN nucleation layer. Based on these various observations and results, conclusions or propositions relating to the microstructure are presented.

Novel Design of MOCVD Reactor with Three Radial Inward Flows for Epitaxial Growth of GaN Thin Films

2011 ◽  
Vol 308-310 ◽  
pp. 1037-1040
Author(s):  
Liao Qiao Yang ◽  
Jian Zheng Hu ◽  
Zun Miao Chen ◽  
Jian Hua Zhang ◽  
Alan G. Li
Keyword(s):  
Gas Flow ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Operating Pressure ◽  
Axisymmetric Mode ◽  
Mocvd Reactor ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
D Model

In this paper, a novel super large metal organic chemical vapor deposition (MOCVD) reactor with three inlets located on the periphery of reactor was proposed and numerical evaluation of growth conditions for GaN thin film was characterized. In this design, the converging effects of gas flow in the radial direction could counterbalance the dissipation of metal organics source. CFD was used for the mathematical solution of the fluid flow, temperature and concentration fields. A 2-D model utilizing axisymmetric mode to simulate the gas flow in a MOCVD has been developed. The growth of GaN films using TMGa as a precursor, hydrogen as carrier gas was investigated. The effects of flow rates, mass fraction of various species, operating pressure, and gravity were analyzed and discussed, respectively. The numerical simulation results show all the fields distributions were in an acceptable range.

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