Structural properties of epitaxial TiO2 films grown on sapphire (11$\overline 1$0) by MOCVD

1992 ◽  
Vol 7 (9) ◽  
pp. 2495-2506 ◽  
Author(s):  
H.L.M. Chang ◽  
H. You ◽  
Y. Gao ◽  
J. Guo ◽  
C.M. Foster ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Structural Properties ◽  
Growth Temperature ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Organic Chemical ◽  
Resolution Electron ◽  
Titanium Dioxide Thin Films ◽  
Deposited Films

Titanium dioxide thin films were grown on sapphire (11$\overline 1$0) substrates in a low-pressure metal-organic chemical vapor deposition system at temperatures ranging from 400 to 800 °C. Raman scattering, x-ray diffraction, transmission electron microscopy, and high resolution electron microscopy techniques were employed to characterize the structural properties of the deposited films. The resultant phases and structures of the deposited films depended on both the growth temperature and the substrate surface properties (surface imperfections, steps, etc.). At the growth temperature of 800 °C, single-crystal rutile films were obtained reproducibly with two possible epitaxial relationships. At lower temperatures (400 to 775 °C), the deposited films can be epitaxial or polycrystalline with highly oriented grains. The similarity between the atomic arrangements of the substrate and the film is discussed in detail to explain the observed epitaxial relationships and abruptness of the interfaces.

High Resolution Transmission Electron Microscopy Investigation of the Defect Structure in CdMnTe Layers Grown on GaAs by MOCVD

1987 ◽  
Vol 102 ◽  
Author(s):  
J. H. Mazur ◽  
P. Grodzinski ◽  
A. Nouhi ◽  
R. J. Stirn
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Organic Chemical ◽  
Orientation Relationships ◽  
Transmission Electron ◽  
Microscopy Investigation ◽  
Resolution Electron

ABSTRACTElectron diffraction and high resolution electron microscopy were used for analysis of Cd1−xMnxTe films grown on (100)2°[011] GaAs substrates by metal organic chemical vapor deposition (MOCVD) at 420°C (x=O.3) and 450°C (x=0.5). It has been found that these two conditions produce dramatically different microstructures. Two orientation relationships of the epilayers with respect to the substrate were observed. It is suggested that this phenomenon may be related to GaAs substrate surface morphology.

X-Ray-Optical Multilayer Structures Studied Using High Resolution Electron Microscopy.

1986 ◽  
Vol 77 ◽  
Author(s):  
Mary Beth Stearns ◽  
Amanda K. Petford-Long ◽  
C.-H. Chang ◽  
D. G. Stearns ◽  
N. M. Ceglio ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Substrate Surface ◽  
High Resolution Electron Microscopy ◽  
Atomic Scale ◽  
Degree Of Crystallinity ◽  
Multilayer Systems ◽  
Layer Width ◽  
X Ray ◽  
Resolution Electron

ABSTRACTThe technique of high resolution electron microscopy has been used to examine the structure of several multilayer systems (MLS) on an atomic scale. Mo/Si multilayers, in use in a number of x-ray optical element applications, and Mo/Si multilayers, of interest because of their magnetic properties, have been imaged in cross-section. Layer thicknesses, flatness and smoothness have been analysed: the layer width can vary by up to 0.6nm from the average value, and the layer flatness depends on the quality of the substrate surface for amorphous MLS, and on the details of the crystalline growth for the crystalline materials. The degree of crystallinity and the crystal orientation within the layers have also been investigated. In both cases, the high-Z layers are predominantly crystalline and the Si layers appear amorphous. Amorphous interfacial regions are visible between the Mo and Si layers, and crystalline cobalt suicide interfacial regions between the Co and Si layers. Using the structural measurements obtained from the HREM results, theoretical x-ray reflectivity behaviour has been calculated. It fits the experimental data very well.

Effect of Growth Temperature on Cobalt-Doped TiO2 Thin Films Deposited on Si (100) Substrate by MOCVD Technique

2014 ◽  
Vol 896 ◽  
pp. 192-196 ◽  
Author(s):  
Aip Saripudin ◽  
H. Saragih ◽  
Khairurrijal ◽  
Khairurrijal ◽  
Pepen Arifin
Keyword(s):  
Thin Films ◽  
Growth Temperature ◽  
Anatase Phase ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Vapor Deposition Technique ◽  
Metal Organic ◽  
Titanium Dioxide Thin Films ◽  
Organic Chemical Vapor Deposition

Co:TiO2 (cobalt-doped titanium dioxide) thin films have been deposited on the n-type Si (100) substrate at the temperatures range of 325°C 450°C using MOCVD (metal organic chemical vapor deposition) technique. We investigated the effect of growth temperature on the structural and morphological quality of Co:TiO2 thin films. The structure of Co:TiO2 thin films were characterized by XRD while the morphology and the thickness of films were characterized by SEM. The XRD results reveal that all films show the anatase structure and the dominant orientation of anatase phase depends on the growth temperature. The grain size of crystal increases as the growth temperature increases. We also reveal that the growth rate of Co:TiO2 film has a maximum value at the growth temperature of 400°C.

Atomic Scale Aluminum and Strain Distribution in a Gan/AlxGa1−XN Heterostructure

1997 ◽  
Vol 482 ◽  
Author(s):  
Christian Kisielowski ◽  
Olaf Schmidt ◽  
Jinwei Yang
Keyword(s):  
Three Dimensional ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Atomic Scale ◽  
Organic Chemical ◽  
Well Test ◽  
Lattice Constants ◽  
Resolution Electron ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

AbstractA GaN/AlxGalxN multi-quantum well test structure with Al concentrations 0 ≤ xAl ≤ 1 was utilized to investigate the growth of AlxGal–xN barrier layers deposited by metal organic chemical vapor deposition (MOCVD). A transition from a two dimensional (2D) to a three dimensional (3D) growth mode was observed in AlxGa1–xN barriers with XAl ≥ 0.75. It is argued that the transition occurs because of growth at temperatures that are low compared with the materials melting points Tmelt. The resulting rough AlxGa1–xN surfaces can be planarized by overgrowth with GaN. Quantitative high resolution electron microscopy (HREM) was applied to measure composition and strain profiles across the GaN/AlxGa1−xN stacks at an atomic level. The measurements reveal a substantial variation of lattice constants at the AlxGa1−xN/GaN interfaces that is attributed to an Al accumulation.

High-resolution electron microscopy investigations of stacking faults in Y1Ba2Cu3O7−δ metalorganic chemical vapor deposited thin films

1999 ◽  
Vol 14 (7) ◽  
pp. 2732-2738 ◽  
Author(s):  
Ch. Grigis ◽  
S. Schamm ◽  
D. Dorignac
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
High Resolution ◽  
Image Matching ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron ◽  
Chemical Vapor Deposited ◽  
Structural Imperfections ◽  
Metalorganic Chemical

New structural planar defects in Ba-deficient Y1Ba2Cu3O7−δ (YBCO) (1:1.6:3) thin films grown on NdGaO3 and SrTiO3 substrates by metalorganic chemical vapor deposition have been observed by means of high-resolution electron microscopy. The defects are associated with perturbations of the YBCO “1:2:3” stacking sequences along the c direction, which give rise to structural variants with locally “2:5:7,” “3:4:7,” or “4:6:10” cationic stoichiometries. The defects can be consistently interpreted as CuO–YO–CuO/CuO conversions or YO/BaO (BaO/YO) interconversions in the (a,b) planes and extending over a few nanometers along the c axis. Structural models based on image matching with simulations are proposed for two particular cases. It is thought that these structural imperfections can be effective sites of flux pinning.

Structural Study of Chemical-Vapor-Deposited Diamond Surface by High-Resolution Electron Microscopy

1995 ◽  
Vol 34 (Part 2, No. 6B) ◽  
pp. L782-L785 ◽  
Author(s):  
Nan Jiang ◽  
Akimitsu Hatta ◽  
Jaihyung Won ◽  
Yusuke Mori ◽  
Toshimichi Ito ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Structural Study ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Diamond Surface ◽  
Resolution Electron ◽  
Chemical Vapor Deposited

High-resolution electron microscopy of diamond hexagonal silicon in low pressure chemical vapor deposited polycrystalline silicon

1991 ◽  
Vol 6 (11) ◽  
pp. 2324-2336 ◽  
Author(s):  
Hans Cerva
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Orientation Relationship ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
High Density ◽  
Translation Vector ◽  
Medium Temperature ◽  
First Case ◽  
Resolution Electron

Thin poly-Si layers deposited at 625 °C by LPCVD that are used in silicon technology for microelectronics exhibit a pronounced additional x-ray diffraction peak at about 0.334 nm. High-resolution electron microscopy (HREM) reveals that this peak stems from {010} reflections of a diamond hexagonal (dh) Si phase, which occurs as small inclusions with the orientation relationship (01) ‖ (0001), [011] ‖ [20] to the diamond cubic (dc) Si matrix. Due to the high density of planar faults on {111}, the dh-Si phase also exists in the form of the 2H silicon polytype with the orientation relationship (1) ‖ (0001), [011] ‖ [20]. In the first case the formation of the dh-Si phase may be understood by a multiple twinning transformation process, and in the second case by glide of Shockley partial dislocations on {111} planes. Various other hexagonal polytypes occur, which have all the {010} reflections in common and make a major contribution to the 0.334 nm peak. The medium temperature of 625 °C for layer deposition leads to a 〈011〉 preferential orientation and a high density of twins as well as to high compressive stress in the poly-Si layer itself. This seems to promote the formation of dh-Si. The strong twinning behavior produces a typical tilt grain boundary between adjacent dh-Si grains: [20], (016), Θ = 35°with a translation vector t = 1/2[031] parallel to it. The dh-Si phase vanishes in this poly-Si film after annealing at temperatures above 1000 °C due to grain growth by recrystallization.

Heteroepitaxial Diamond Formed on Silicon Wafer Observed by High Resolution Electron Microscopy

1994 ◽  
Vol 357 ◽  
Author(s):  
Jie Yang ◽  
Zhangda Lin ◽  
Li-Xin Wang ◽  
Sing Jin ◽  
Ze Zhang
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Diamond Films ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Cross Sectional ◽  
Diamond Crystals ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Hot Filament

AbstractDiamond films with high preferential orientation (111) on silicon (100) crystalline orientation substrates had been obtained by hot-filament chemical vapor deposition (HFCVD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and high-resolution cross-sectional transmission electron microscopy (HREM) are used to characterizate the structure and morphology of the synthesised diamond films. Diamond (111) plans had been local grown epitaxially on the Si(100) substrate observed by HREM. SEM photographes show that plane diamond crystals have been obtained.

High-resolution Electron Microscopy of grain Boundary Structures in Yttria-stabilized Cubic Zirconia

2000 ◽  
Vol 654 ◽  
Author(s):  
K. L. Merkle ◽  
L. J. Thompson ◽  
G.-R. Bai ◽  
J. A. Eastman
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Atomic Scale ◽  
Organic Chemical ◽  
Special Technique ◽  
Cubic Zirconia ◽  
Resolution Electron ◽  
Wide Range ◽  
Relaxation Modes

AbstractThe atomic-scale structure of grain boundaries (GBs) in yttria-stabilized cubic zirconia (YSZ) was investigated by high-resolution electron microscopy (HREM). Non-stoichiometric oxides have found a wide range of applications and therefore it is of importance to explore the role of GBs and their atomic-scale relaxation modes. [001] and [110] tilt GBs were examined by HREM in highly textured thin films of YSZ grown by metal-organic chemical vapor deposition (MOCVD). In addition, a special technique was developed to also allow the HREM study of twist and general GBs. GBs and triple junctions show quite dense arrangements of cation atomic columns. The GB core structures in YSZ can be contrasted to the more open structures in stoichiometric cubic oxides, such NiO, which are characterized by a relatively large GB excess volume. This appears to be due to several factors, including the necessary rearrangement of the oxygen sublattice near GBs in a CsCl2 type structure, the redeployment of oxygen vacancies near GBs, and the segregation of Y to the GB. Relative to stoichiometric oxides, such mechanisms provide additional degrees of freedom for atomic relaxations at GBs and the development of low-energy GBs. These additional relaxation modes, which result in GB cation arrangements more akin to metallic systems, are also reflected by Burgers vector dissociations observed in low-angle YSZ GBs.

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