Ge/Si(100) Island and Wetting Layer Composition

2002 ◽  
Vol 749 ◽  
Author(s):  
Yangting Zhang ◽  
Jeff Drucker
Keyword(s):  
Rutherford Backscattering Spectrometry ◽  
Water Soluble ◽  
Wetting Layer ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Substrate Temperatures ◽  
Water Etching ◽  
Layer Composition

ABSTRATCTEtching water soluble Ge-oxides was used to investigate Si interdiffusion into epitaxial Ge / Si(100) samples. The Ge coverage, θGe, was measured using Rutherford backscattering spectrometry (RBS) before and after water etching of samples grown at substrate temperatures between 400 °C and 650 °C. θGewas correlated with sample morphology determined using atomic force microscopy (AFM). The local Ge concentration was qualitatively assessed using energy dispersive x-ray (EDX) analysis. For samples grown at T=400 °C, water completely dissolves the islands and no Ge is detected by RBS. For samples grown at T=600 and 650 °C, AFM detects no change in the surface morphology and RBS indicates that θGedecreases by about 3 monolayers (ML). These results suggest that for growth at T=400 °C, both the islands and wetting layer are relatively pure Ge while for growth at T≥600 °C, the wetting layer is Ge rich compare to the SiGe alloy islands. EDX confirms this conclusion detecting no Ge signal between islands for etched samples grown at T≥600 °C. Our results suggest that for growth at T≥600 °C, Si interdiffusion into islands is through the region underneath the islands instead of from the wetting layer.

Characterization of X-ray irradiated graphene oxide coatings using X-ray diffraction, X-ray photoelectron spectroscopy, and atomic force microscopy

2013 ◽  
Vol 28 (2) ◽  
pp. 68-71 ◽  
Author(s):  
Thomas N. Blanton ◽  
Debasis Majumdar
Keyword(s):  
Atomic Force Microscopy ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
High Energy ◽  
X Ray Diffraction ◽  
Carbon Phase ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After

In an effort to study an alternative approach to make graphene from graphene oxide (GO), exposure of GO to high-energy X-ray radiation has been performed. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) have been used to characterize GO before and after irradiation. Results indicate that GO exposed to high-energy radiation is converted to an amorphous carbon phase that is conductive.

Epitaxial BaTiO3 Thin Films on Different Substrates for Optical Waveguide Applications

1999 ◽  
Vol 597 ◽  
Author(s):  
M. Siegert ◽  
Judit G. Lisoni ◽  
C. H. Lei ◽  
A. Eckau ◽  
W. Zander ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Waveguides ◽  
Rutherford Backscattering Spectrometry ◽  
Optical Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Ion Channeling ◽  
Atomic Force ◽  
Transmission Electron

AbstractIn the process of developing thin film electro-optical waveguides we investigated the influence of different substrates on the optical and structural properties of epitaxial BaTiO3 thin films. These films are grown by on-axis pulsed laser deposition (PLD) on MgO(100), MgAl2O4(100), SrTiO3(100) and MgO buffered A12O3(1102) substrates. The waveguide losses and the refractive indices were measured with a prism coupling setup. The optical data are correlated to the results of Rutherford backscattering spectrometry/ion channeling (RBS/C). X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM). BaTiO3 films on MgO(100) substrates show planar waveguide losses of 3 dB/cm and ridge waveguide losses of 5 dB/cm at a wavelength of 633 nm.

Stress origin and relaxation in epitaxial AlN thin films on SiC

2001 ◽  
Vol 696 ◽  
Author(s):  
Ravi Bathe ◽  
R.D. Vispute ◽  
Daniel Habersat ◽  
R. P. Sharma ◽  
T. Venkatesan ◽  
...  
Keyword(s):  
Thin Films ◽  
Rutherford Backscattering Spectrometry ◽  
Wide Band ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
X Ray ◽  
Force Microscopy ◽  
Ion Channeling ◽  
Atomic Force ◽  
Highly Strained

AbstractWe have investigated the epitaxy, surfaces, interfaces, and defects in AlN thin films grown on SiC by pulsed laser deposition. The stress origin, evolution, and relaxation in these films is reported. The crystalline structure and surface morphology of the epitaxially grown AlN thin films on SiC (0001) substrates have been studied using x-ray diffraction (θ–2θ, ω, and Ψ scans) and atomic force microscopy, respectively. The defect analysis has been carried out by using Rutherford backscattering spectrometry and ion channeling technique. The films were grown at various substrate temperatures ranging from room temperature to 1100 °C. X-ray diffraction measurements show highly oriented AlN films when grown at temperatures of 750- 800 °C, and single crystals above 800 °C. The films grown in the temperature range of 950 °C to 1000 °C have been found to be highly strained, whereas the films grown above 1000 °C were found to be cracked along the crystallographic axes. The results of stress as a function of growth temperature, thermal mismatch, growth mode, and buffer layer thickness will be presented, and the implications of these results for wide band gap power electronics will be discussed.

Fabrication of A Barium Titanate-Strontium Titanate Strained Layer Superlattice

1995 ◽  
Vol 397 ◽  
Author(s):  
S.D. Harkness ◽  
R.K. Singh
Keyword(s):  
Critical Thickness ◽  
Laser Deposition ◽  
Processing Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Order Of Magnitude ◽  
Strained Layer Superlattice ◽  
Substrate Temperatures

ABSTRACTA thin film superlattice heterostructure composed of alternating BaTiO3 and SrTiO3 layers was grown on a thin YBa2Cu3O7 electrode templated on a (100) SrTiO3 wafer using the pulsed laser deposition method. Stranski-Krastanov nucleation of the layers was demonstrated using atomic force microscopy (AFM) when processing conditions were maintained at 6 millitorr oxygen partial pressure, and 550 °C substrate temperatures. High-resloution x-ray diffraction (HRXRD) measurements indicate that all the deformation was concentrated in the BaTiO3 layers with c/a extension to approximately 1.08. Rutherford backscattering spectroscopy (RBS) results indicate excellent crystallinity in the heterostructure. The microstructural data suggests that the theoretical critical thickness of the film has been surpassed by an order of magnitude.

GaZnO as a Transparent Electrode to Silicon Carbide

2012 ◽  
Vol 717-720 ◽  
pp. 849-852
Author(s):  
Jung Ho Lee ◽  
Ji Hong Kim ◽  
Kang Min Do ◽  
Byung Moo Moon ◽  
Sung Jae Joo ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Hall Effect Measurement ◽  
Transparent Electrode ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Structural And Electrical Properties ◽  
Substrate Temperature Increase ◽  
Substrate Temperatures

The characteristics of Ga-doped zinc oxide (GaZnO) thin films deposited at different substrate temperatures (TS~250 to 550oC) on 4H-SiC have been investigated. Structural and electrical properties of GaZnO thin film on n-type 4H-SiC (100)were investigated by using x-ray diffraction, atomic force microscopy (AFM), Hall effect measurement, and Auger electron spectroscopy (AES). Hall mobility is found to increase as the substrate temperature increase from 250 to 550 oC, whereas the lowest resistivity (~3.3 x 10-4 Ωcm) and highest carrier concentration (~1.33x1021cm-3) values are observed for the GaZnO films deposited at 400 oC. It has been found that the c-axis oriented crystalline quality as well as the relative amount of activated Ga3+ Introduction ions may affect the electrical properties of GaZnO films on SiC.

Nanoscale Surface Modifications by Magnetic Field-Assisted Finishing

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Raul E. Riveros ◽  
Jared N. Hann ◽  
Curtis R. Taylor ◽  
Hitomi Yamaguchi
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Microelectromechanical Systems ◽  
Clear Understanding ◽  
X Ray ◽  
Surface Features ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Process Material

A magnetic field-assisted finishing (MAF) process has been developed to reduce the sidewall surface roughness of the 5–20 μm wide curvilinear pores of microelectromechanical systems micropore X-ray optics to <1 nm Rq. Although the feasibility of this process has been demonstrated on these optics, a clear understanding of the MAF process' material removal mechanisms has not been attained. In an attempt to discover these mechanisms, the MAF process is applied to a flat workpiece, allowing for direct observation and tracking of changes to distinctive surface features before and after MAF. Atomic force microscopy, field-emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy are used to analyze the surface morphology and composition with respect to finishing time. These observations suggest that the MAF process modified the surface, reducing surface roughness (from 0.8 nm to 0.6 nm Rz on silicon) by removing relatively low-wavelength surface features. Moreover, the MAF process appears to modify the surface mechanically.

Preparation of Cu(In,Ga)Se2 thin films at low substrate temperatures

2001 ◽  
Vol 16 (2) ◽  
pp. 394-399 ◽  
Author(s):  
S. Nishiwaki ◽  
T. Satoh ◽  
Y. Hashimoto ◽  
T. Negami ◽  
T. Wada
Keyword(s):  
Thin Films ◽  
Surface Composition ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
X Ray Diffraction ◽  
Monitoring Method ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Substrate Temperatures

Cu(In,Ga)Se2(CIGS) thin films were prepared at substrate temperatures of 350 to 500 °C. The (In,Ga)2Se2 precursor layers were deposited on Mo coated soda-lime glass and then exposed to Cu and Se fluxes to form CIGS films. The surface composition was probed by a real-time composition monitoring method. The CIGS films were characterized by x-ray diffraction, energy dispersive x-ray spectroscopy, secondary ion mass spectroscopy, and atomic force microscopy. The transient formation of a Cu–Se phase with a high thermal emissivity was observed during the deposition of Cu and Se at a substrate temperature of 350 °C. Faster diffusion of In than Ga from the (In,Ga)2Se3 precursor to the newly formed CIGS layer was observed. A growth model for CIGS films during the deposition of Cu and Se onto (In,Ga)2Se3 precursor is proposed. A solar cell using a CIGS film prepared at about 350 °C showed an efficiency of 12.4%.

Epitaxial Batio3 and Knbo3 Thin Films On Various Substrates for Optical Waveguide Applications

1996 ◽  
Vol 441 ◽  
Author(s):  
L. Beckers ◽  
W. Zander ◽  
J. Schubert ◽  
P. Leinenbach ◽  
Ch. Buchal ◽  
...  
Keyword(s):  
Optical Materials ◽  
Rutherford Backscattering Spectrometry ◽  
X Ray Diffraction ◽  
Crystalline Perfection ◽  
Rocking Curve ◽  
X Ray ◽  
Flat Surfaces ◽  
Force Microscopy ◽  
Atomic Force ◽  
Yield Values

AbstractTechnologically interesting optical materials such as BaTiO3 and KnbO3 are difficult to grow as single crystals of large dimensions. Thin film techniques can overcome this problem by synthesizing these materials on commercially available substrates. We demonstrate the deposition of single crystalline BaTiO3 and KnbO3 on MgO, SrTiO3 and buffered MgO substrates by Pulsed Laser Deposition (PLD). The samples are characterized by Rutherford Backscattering Spectrometry / Channeling (RBS/C), X-Ray Diffraction (XRD) and Atomic Force Microscopy (AFM). We found excellent crystalline quality, confirmed by RBS/C minimum yield values of 2 % and a FWHM of 0.36° of the BaTiO3(002) rocking curve. Even films of a few microns thickness have been grown without loss of crystalline perfection, and all films show very flat surfaces. The RMS roughness of a 950 nm BaTiO3 film was found to be 1.1 nm.

Heteroepitaxial Growth of Epitaxial C60-Thin Films on Mica(001)

1994 ◽  
Vol 359 ◽  
Author(s):  
S. Henke ◽  
K.H. Thürer ◽  
S. Geier ◽  
B. Rauschenbach ◽  
B. Stritzker
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Substrate Temperature ◽  
Room Temperature ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Substrate Temperatures

ABSTRACTOn mica(001) thin C60-films are deposited by thermal evaporation at substrate temperatures from room temperature up to 225°C. The dependence of the structure and the epitaxial alignment of the thin C60-films on mica(001) on the substrate temperature and the film thickness up to 1.3 μm at a well-defined deposition rate (0.008 nm/s) is investigated by atomic force microscopy and X-ray diffraction. The shape and the size of the C60-islands, which have an influence on the film quality at larger film thicknesses, are sensitively dependent on the substrate temperature. At a film thickness of 200 nm the increase of the substrate temperature up to 225°C leads to smooth, completely coalesced epitaxial C60-thin films characterized by a roughness smaller than 1.5 nm, a mosaic spread Δω of 0.1° and an azimuthal alignment ΔΦ of 0.45°.

Enhancing Titanium Stability in Fusayama Saliva Using Electrochemical Elaboration of TiO2 Nanotubes

2008 ◽  
Vol 59 (6) ◽  
Author(s):  
Isabela Man ◽  
Cristian Pirvu ◽  
Ioana Demetrescu
Keyword(s):  
Tio2 Nanotubes ◽  
Room Temperature ◽  
Large Range ◽  
Stability Evaluation ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
The Stability ◽  
Tube Structure

Titanium having low density, stability and biocompatibility, is one of the most promising biomaterial of the century even with the natural passive stratum [1,2], but building a nano-tube structure in the last decade using various procedure could lead also to an improvement of a quite large range of properties important in applied chemistry. The aim of the paper is to elaborate electrochemically TiO2 nanotubes and to evaluate the stability increase of Titanium in Fusayama saliva changing the surface morphology from micro TiO2 to TiO2 nanotubes. Anodization at room temperature in a mixture of (NH4)2SO4 and NH4F, was the choice of nanotubes structures elaboration, and cyclic voltammetry was the procedure of stability evaluation. The surface analysis was performed using scanning electron microscopy (SEM), energy-dispersive X-ray microanalysis (EDAX), and atomic force microscopy before and after anodization.

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