Xps Analysis of Y-Ba-Cu-O and Zr-O Thin Films and Interfaces with Silicon Substrates

1989 ◽  
Vol 169 ◽  
Author(s):  
D.B. Fenner ◽  
A.M. Viano ◽  
G.A.N. Connell ◽  
J.B. Boyce ◽  
D.K. Fork ◽  
...  
Keyword(s):  
Thin Films ◽  
Buffer Layers ◽  
Silicon Substrates ◽  
Cross Sectional ◽  
Si Substrates ◽  
Bulk Ybco ◽  
Transmission Electron ◽  
Oxide Etching ◽  
Lattice Images ◽  
Zirconia Films

AbstractThin films of Y1Ba2Cu3Ox,ZrO2, and yttria-stabilized zirconia (YSZ) have been deposited on Si(100) by the UV-laser ablation technique, and characterized by several techniques including x-ray photoemission spectroscopy (XPS) and cross-sectional transmission electron microscopy (XTEM). Si substrates were prepared by several techniques including thermal oxidation, and oxide etching and passivation by hydrogen termination. Certain of these YBCO films (= 250 nm thick) deposited on YSZ buffer layers have excellent superconducting properties. Other YBCO and zirconia films, deposited to 2-5 nm thickness and transferred under dry N2 into UHV, allowed XPS evaluation of the thermal and chemical stability of the interfaces and nearby regions. 2-nm films of YBCO on 15-nm films of SiO2/Si, deposited at 550–670 °C, showed Cu 2p core-level XPS lines similar to those of bulk YBCO (i.e., Cu II) but with two components due to reactions. The Si 2p line showed formation of silica on the YBCO surface at 670 °C and of silicate at 550 °C. XTEM lattice images showed that use of H-terminated Si produced superior interfaces with the zirconia films.

Direct Deposition Reactions Between Nickel and Silicon Substrates

1993 ◽  
Vol 311 ◽  
Author(s):  
Lin Zhang ◽  
Douglas G. Ivey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Substrates ◽  
Silicide Formation ◽  
Cross Sectional ◽  
Deposition Rates ◽  
Plan View ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron

ABSTRACTSilicide formation through deposition of Ni onto hot Si substrates has been investigated. Ni was deposited onto <100> oriented Si wafers, which were heated up to 300°C, by e-beam evaporation under a vacuum of <2x10-6 Torr. The deposition rates were varied from 0.1 nm/s to 6 nm/s. The samples were then examined by both cross sectional and plan view transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy and electron diffraction. The experimental results are discussed in terms of a new kinetic model.

Microstructural Studies of Ferroelectric Bi2VO5.5 Thin Films With LaNiO3 Electrodes

1994 ◽  
Vol 341 ◽  
Author(s):  
D. Prasad Beesabathina ◽  
L. Salmanca-Riba ◽  
M. S. Hegde ◽  
K. M. Satyalakshmi ◽  
K. V. R. Prasad ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Direction ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
Epitaxial Relationship ◽  
X Ray ◽  
Transmission Electron ◽  
Lattice Images ◽  
Relationship Of ◽  
Microstructural Studies

AbstractThin films of Bi2VO5.5 (BVO), a vanadium analog of the n = I member of the Aurivillius family, have been prepared by pulsed laser deposition. The BVO films grow along the [001] direction on LaNiO3(LNO) and YBa2Cu3O7 (YBCO) electrode buffer layers on LaA- IO3(LAO) substrates as obtained from X-ray diffraction studies. The microstructure of the films and of the interfaces within the film and between the film and the substrate were characterized using transmission electron microscopy. The in-plane epitaxial relationship of the rhombohedral LNO on perovskite LAO was [100] LNO // [100] LAO and [001] LNO // [001] LAO. High resolution lattice images showed a sharp interface between LNO and LAO. However, the LNO film is twinned with a preferred orientation along the growth direction. The BVO layer is single crystalline on both LNO/LAO and YBCO/LAO with the caxis parallel to the growth direction except for a thin layer of about 400 Å at the interface which is polycrystalline.

Stress and Microstructure Evolution in Compositionally Graded Al1-xGaxN Buffer Layers for GaN Growth on Si

2005 ◽  
Vol 892 ◽  
Author(s):  
Xiaojun Weng ◽  
Srinivasan Raghavan ◽  
Elizabeth C Dickey ◽  
Joan M Redwing
Keyword(s):  
Buffer Layer ◽  
Compressive Stress ◽  
Microstructure Evolution ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Cross Sectional ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Annihilation

AbstractWe have studied the evolution of stress and microstructure of compositionally graded Al1-xGaxN (0 ≤ x ≤1) buffer layers on (111) Si substrates with varying thicknesses. In-situ stress measurements reveal a tensile-to-compressive stress transition that occurs near the half-thickness in each buffer layer. Cross-sectional transmission electron microscopy (TEM) shows a significant reduction in threading dislocation (TD) density in the top half of the buffer layer, suggesting that the compressive stress enhances the threading dislocation annihilation. The composition of the buffer layers varies linearly with thickness, as determined by X-ray energy dispersive spectrometry (XEDS). The composition grading-induced compressive stress offsets the tensile stress introduced by microstructure evolution, thus yielding a tensile-to-compressive stress transition at x ≈ 0.5.

Epitaxial growth of yBa2Cu3O7-x films on Si substrates with buffer layers

1989 ◽  
Vol 47 ◽  
pp. 182-183
Author(s):  
D. M. Hwang ◽  
R. Ramesh ◽  
X. D. Wu ◽  
A. Inam ◽  
M. S. Hegde ◽  
...  
Keyword(s):  
Thin Films ◽  
Rf Magnetron Sputtering ◽  
Buffer Layers ◽  
Substrate Holder ◽  
X Ray Diffraction ◽  
Critical Temperatures ◽  
Tem Analysis ◽  
Si Substrates ◽  
Transmission Electron ◽  
Current Densities

Several groups have prepared nearly-single-crystalline YBa2Cu3O7-X thin films on SrTiO3 substrates with critical temperatures of zero resistivity (Tα) exceeding 90 K and critical current densities at 77 K (Jc,77k) exceeding 106 A/cm2. However, films prepared on Si substrates, either directly or with buffer layers, are usually polycrystalline and with much lower Tα and Jc. Recently, much-improved YBa2Cu3O7-X thin films have been prepared on Si substrates with double buffer layers, BaTiO3 and MgAl2O4. Miura et al. prepared the films by rf magnetron sputtering at 640°C substrate holder temperature and their best as-deposited film exhibits Tα = 70 K and Jc,40k = 4 × 104 A/cm2. Wu et al. prepared the films by pulsed laser deposition at 650°C substrate holder temperature and their best film exhibits Tα = 87 K and Jc,77K = 6 × 104 A/cm2. X-ray diffraction studies indicated that the films are orientationally locked with the Si substrates. Here we present the transmission electron microscopy (TEM) analysis of the laser deposited films and show the epitaxial relations between the buffer layers and the Si substrates, as well as between the YBa2Cu3O7-X flims and the buffer layers. Defect generating mechanisms and possibilities for improving the crystalline properties of the YBa2Cu3O7-X films, and consequently the superconducting properties, will be discussed.

TiSi2 Thin Films Formed on Crystalline and Amorphous Silicon

1990 ◽  
Vol 182 ◽  
Author(s):  
Z.G. Xiao ◽  
H. Jiang ◽  
J. Honeycutt ◽  
C.M. Osburn ◽  
G. Mcguire ◽  
...  
Keyword(s):  
Thin Films ◽  
Amorphous Silicon ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Plan View ◽  
Si Substrates ◽  
Transmission Electron ◽  
Amorphous Si ◽  
Transformation Stress ◽  
Silicon Interface

AbstractTiSi2 thin films were formed on crystalline and amorphous silicon substrates obtained by Ge+ and Ge++B+ implantation and optional subsequent annealing. Transmission electron microscopy, X-ray diffraction and electrical resistivity analysis revealed that the silicide formed on amorphous Si has more tendency to have a C54 structure rather than the metastable C49 structure. Also, the grain size is smaller and the silicide/silicon interface is smoother for silicides formed on amorphous Si. Comparison between implanted and unimplanted, (100) and (111) Si substrates indicated that the origin of the differences can be attributed to the latent energy stored in amorphous silicon, which favors the silicide with fine grains and promotes the transformation to the C54 phase. Non-random distribution of planar defects in C49 grains has been observed by plan-view TEM. A proposal that these defects are transformation stress induced microtwins is presented.

Influence of the microstructure of Pt/Si substrates on textured growth of barium titanate thin films prepared by pulsed laser deposition

1998 ◽  
Vol 13 (2) ◽  
pp. 368-375 ◽  
Author(s):  
Cheol Seong Hwang ◽  
Mark D. Vaudin ◽  
Peter K. Schenck
Keyword(s):  
Thin Films ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Growth Behavior ◽  
Laser Deposition ◽  
Silicon Substrates ◽  
Epitaxial Relationship ◽  
Si Substrates ◽  
Transmission Electron

Pt-coated silicon substrates with strong (111) Pt texture were annealed in an oxidizing atmosphere at temperatures from 500 °C to 750 °C. BaTiO3 thin films were deposited by pulsed laser ablation on the substrates. Observation by transmission electron microscopy showed that the substrate anneal caused the formation of TiO2 in the Pt layer, accompanied by the formation of a high density of faceted protrusions on the Pt surface, particularly at the higher anneal temperatures. The Pt protrusions had (111) facets, parallel to the substrate surface, on which (100)-oriented BaTiO3 grains were observed. BaTiO3 grains with an epitaxial relationship to the Pt lattice were observed on inclined facets of the Pt protrusions [which were not (111) planes], and also on the nonplanar regions of the Pt surface. These epitaxial BaTiO3 grains had (111) preferred orientation relative to the substrate surface. Thus, the BaTiO3 films displayed bimodal growth behavior, with both (100) texture and (111) epitaxy. We propose a model for this behavior based on surface energy considerations.

Evaluation of Anti-Phase-Boundaries in GaAs/Si Heterostructures by Transmission Electron Microscopy

1989 ◽  
Vol 148 ◽  
Author(s):  
O. Ueda ◽  
T. Soga ◽  
T. Jimbo ◽  
M. Umeno
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Three Dimensional ◽  
Buffer Layers ◽  
Phase Boundaries ◽  
Cross Sectional ◽  
Si Substrates ◽  
Transmission Electron ◽  
Strained Layer Superlattices ◽  
And Behavior

ABSTRACTThe nature and behavior of anti-phase-boundaries in GaAs/Si heterostructures using GaP, GaP/GaAsP and GaAsP/GaAs strained layer superlattices as intermediate buffer layers, have been investigated by transmission electron microscopy. It has been found that anti-phasedomains are very complicated three dimensional polygons consisting of several sub-boundaries in different orientations. Self-annihilation of anti-phase-domains during crystal growth of GaAs on (001)just or (001)2°off Si substrates is directly observed for the first time through planview and cross-sectional observations. Based on these findings, a mechanism of annihilation of these domains is proposed.

Tisi2 Thin Films Formed on Crystalline and Amorphous Silicon

1990 ◽  
Vol 181 ◽  
Author(s):  
Z.G. Xiao ◽  
H. Jiang ◽  
J. Honeycutt ◽  
C.M. Osburn ◽  
G. McGuire ◽  
...  
Keyword(s):  
Thin Films ◽  
Amorphous Silicon ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Plan View ◽  
Si Substrates ◽  
Transmission Electron ◽  
Amorphous Si ◽  
Transformation Stress ◽  
Silicon Interface

ABSTRACTTiSi2 thin films were formed on crystalline and amorphous silicon substrates obtained by Ge+ and Ge++B+ implantation and optional subsequent annealing. Transmission electron microscopy, X-ray diffraction and electrical resistivity analysis revealed that the silicide formed on amorphous Si has more tendency to have a C54 structure rather than the metastable C49 structure. Also, the grain size is smaller and the silicide/silicon interface is smoother for silicides formed on amorphous Si. Comparison between implanted and unimplanted, (100) and (111) Si substrates indicated that the origin of the differences can be attributed to the latent energy stored in amorphous silicon, which favors the silicide with fine grains and promotes the transformation to the C54 phase. Non-random distribution of planar defects in C49 grains has been observed by plan-view TEM. A proposal that these defects are transformation stress induced microtwins is presented.

Electron Energy Analysis of Germanium and Silica Layers on Silicon Substrates

1975 ◽  
Vol 33 ◽  
pp. 96-97
Author(s):  
R. W. Ditchfield ◽  
A. G. Cullis
Keyword(s):  
Epitaxial Growth ◽  
Electron Energy ◽  
Silicon Substrates ◽  
Secondary Phases ◽  
Si Substrates ◽  
Transmission Electron ◽  
Layer Structures ◽  
Si Films ◽  
Electron Energy Loss ◽  
Growth Centres

An energy analyzing transmission electron microscope of the Möllenstedt type was used to measure the electron energy loss spectra given by various layer structures to a spatial resolution of 100Å. The technique is an important, method of microanalysis and has been used to identify secondary phases in alloys and impurity particles incorporated into epitaxial Si films.Layers Formed by the Epitaxial Growth of Ge on Si Substrates Following studies of the epitaxial growth of Ge on (111) Si substrates by vacuum evaporation, it was important to investigate the possible mixing of these two elements in the grown layers. These layers consisted of separate growth centres which were often triangular and oriented in the same sense, as shown in Fig. 1.

Characterization of reactive phase formation in sputter-deposited Ni/Al multilayer thin films using TEM

1996 ◽  
Vol 54 ◽  
pp. 1000-1001
Author(s):  
G. Lucadamo ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Dark Field ◽  
Nickel Layer ◽  
Multilayer Thin Films ◽  
Cross Sectional ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Sputter Deposited ◽  
Constant Heating

The subject of reactive phase formation in multilayer thin films of varying periodicity has stimulated much research over the past few years. Recent studies have sought to understand the reactions that occur during the annealing of Ni/Al multilayers. Dark field imaging from transmission electron microscopy (TEM) studies in conjunction with in situ x-ray diffraction measurements, and calorimetry experiments (isothermal and constant heating rate), have yielded new insights into the sequence of phases that occur during annealing and the evolution of their microstructure.In this paper we report on reactive phase formation in sputter-deposited lNi:3Al multilayer thin films with a periodicity A (the combined thickness of an aluminum and nickel layer) from 2.5 to 320 nm. A cross-sectional TEM micrograph of an as-deposited film with a periodicity of 10 nm is shown in figure 1. This image shows diffraction contrast from the Ni grains and occasionally from the Al grains in their respective layers.

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