Characterization of the near-surface region in ion-exchanged glass waveguides

2001 ◽  
Author(s):  
Flavio Horowitz ◽  
Marcelo B. Pereira ◽  
M. Behar ◽  
Luiz C. Barbosa ◽  
Stefano Pelli ◽  
...  
Keyword(s):  
Surface Region ◽  
Near Surface ◽  
Glass Waveguides

BIC Formation and Boron Diffusion in Relaxed Si0.8Ge0.2

2004 ◽  
Vol 810 ◽  
Author(s):  
R. T. Crosby ◽  
L. Radic ◽  
K. S. Jones ◽  
M. E. Law ◽  
P.E. Thompson ◽  
...  
Keyword(s):  
Surface Region ◽  
Extended Defects ◽  
Defect Structures ◽  
Boron Diffusion ◽  
Plan View ◽  
Near Surface ◽  
Transmission Electron ◽  
Secondary Ion ◽  
Ion Implanted

ABSTRACTThe relationships between Boron Interstitial Cluster (BIC) evolution and boron diffusion in relaxed Si0.8Ge0.2 have been investigated. Structures were grown by Molecular Beam Epitaxy (MBE) with surface boron wells of variant composition extending 0.25 [.proportional]m into the substrate, as well as boron marker layers positioned 0.50 [.proportional]m below the surface. The boron well concentrations are as follows: 0, 7.5×1018, 1.5×1019, and 5.0×1019 atoms/cm3. The boron marker layers are approximately 3 nm wide and have a peak concentration of 5×1018 atoms/cm3. Samples were ion implanted with 60 keV Si+ at a dose of 1×1014 atoms/cm2 and subsequently annealed at 675°C and 750°C for various times. Plan-view Transmission Electron Microscopy (PTEM) was used to monitor the agglomeration of injected silicon interstitials and the evolution of extended defects in the near surface region. Secondary Ion Mass Spectroscopy (SIMS) concentration profiles facilitated the characterization of boron diffusion behaviors during annealing. Interstitial supersaturation conditions and the resultant defect structures of ion implanted relaxed Si0.8Ge0.2 in both the presence and absence of boron have been characterized.

The Characterization of WC-Co Based Materials Boronized within Molten Salt Bath

2008 ◽  
Vol 144 ◽  
pp. 261-266 ◽  
Author(s):  
Sakıp Köksal
Keyword(s):  
Molten Salt ◽  
Physical Vapor Deposition ◽  
Surface Region ◽  
Salt Bath ◽  
Functionally Graded ◽  
Near Surface ◽  
Diffusion Treatment ◽  
Physical Deposition ◽  
Molten Salt Bath

Coated WC-Co based cutting tool materials are widely used in machining applications. However some of the coating techniques, such as physical vapor deposition (PVD), involve only the physical deposition of coating layers which are prone to bulk delamination in some applications. Therefore functionally graded microstructure through diffusion is an efficient and widely used methods to improve the performance of coated WC-Co tools. In this work ISO P25, WC-Co based inserts were subjected to a thermochemical diffusion treatment by boronizing in a molten salt bath. The process was performed at 900, 1000, and 1100 °C for 1, 2 and 4 h. SEM, X-ray, EDS and microhardness analysis were performed on the samples. It was found that boron containing hard phases of W 2 B 5 , CoB, W 2 CoB 2 and WCoB were formed within the boronized region, occupying the grain boundary areas. An average microhardness value of 3600 HK 0.01 was measured in the near surface region which is substantially higher than the value of 1418 HK 0.01 representing the inner sections of the material.

Characterization of Material Phases on the Surface and in the Near-Surface Region of Scandate Cathodes

2020 ◽  
Author(s):  
Xiaotao Liu ◽  
Matthew J. Beck ◽  
T. John Balk ◽  
Bernard K. Vancil
Keyword(s):  
Surface Region ◽  
Near Surface

Characterization of Defects Created in Silicon Due to Etching in Low-Pressure Plasmas Containing Fluorine and Oxygen

1995 ◽  
Vol 396 ◽  
Author(s):  
I. A. Buyanova ◽  
A. Henry ◽  
B. Monemar ◽  
J. L. Lindström ◽  
A. Lamprecht ◽  
...  
Keyword(s):  
Deep Level ◽  
Surface Region ◽  
Energy Shift ◽  
Low Pressure ◽  
Extended Defects ◽  
Near Surface ◽  
Defect Complexes ◽  
Radiation Induced ◽  
Dlts Spectra

AbstractDefect characterization in n-type silicon after the reactive ion etching (RIE) in low-pressure plasmas containing fluorine and oxygen is performed by using photoluminescence (PL) and deep level transient spectroscopies (DLTS). It is shown that RIE treatment results in the formation of (i) luminescence centers giving rise to the C- and G- excitonic lines and broad emission bands related to radiation-induced defect complexes and extended defects and (ii) several electron traps located at 0.16 eV, 0.26 eV, 0.43 eV and 0.58 eV below the conduction band. The addition of oxygen to the SF6 and CF4 plasma is shown to cause nonuniform stress in the near surface region. This stress is responsible for the experimentally observed splitting of the C- and G-excitonic lines, a low energy shift of the phosphorous bound exciton lines, as well as the splitting of the DLTS spectra. It is shown that the stress field is highly inhomogeneous across the wafer, and is rather related to the RIE-induced extended defects than caused by the reaction layer formed on the Si surface.

scholarly journals Microstructural Characterization of Iron Implanted Sapphire Nanocomposites

1994 ◽  
Vol 373 ◽  
Author(s):  
Shelly X. Ren ◽  
Carl J. Mchargue ◽  
L. F. Allard ◽  
Y. Chen ◽  
J. D. Hunn ◽  
...  
Keyword(s):  
Oxygen Vacancies ◽  
High Technology ◽  
Microstructural Characterization ◽  
Surface Region ◽  
Luminescence Spectra ◽  
Near Surface ◽  
Transmission Electron ◽  
F Center ◽  
Damage Depth

AbstractNanocomposites of iron in sapphire (α-A12 O3) prepared by ion implantation have been studied as a model to investigate the potential of such materials for applications in high technology areas. The implantation was performed with 160 keV ions at several doses; the nanocomposites were then annealed at selected temperatures between 700 and 1400°C in an Ar-4&H2 atmosphere for 1 hour. Rutherford backscattering spectroscopy and high resolution transmission electron microscopy (TEM) were used to characterize the structure of these nanocomposites. Measurements showed that damage depth extended to about 300 nm and the embedded iron extended to about 200 nm. This region became amorphous when the fluence reaches 2x1017 Fe/cm2 at this energy. At this dose, oriented precipitates with diameters of 2 to 3 nm were identified by TEM techniques as α-Fe which had the following orientation relationship with the sapphire matrix: <111>Fe||<310>Sapphire and (011)Fe||{006}sapphire. Thermal annealing could be used to restore the crystallinity to the damaged near-surface region, to form the metallic colloids, and also to coarsen the precipitates. The optical density and luminescence spectra were also measured. The predominant defects were oxygen vacancies with two electrons (F center) at the known absorption peak of 200 nm.

Structural characterization of SiGe and SiGe:C heterostructures using a combination of X-ray scattering methods

2004 ◽  
Vol 19 (1) ◽  
pp. 49-52 ◽  
Author(s):  
J. F. Woitok
Keyword(s):  
Structural Characterization ◽  
Surface Region ◽  
X Ray Diffraction ◽  
Near Surface ◽  
Xrd Pattern ◽  
X Ray ◽  
X Ray Scattering ◽  
Single Method ◽  
Ray Scattering

This study is about the structural properties of SiGe and SiGe:C heteroepitaxial layers on Si (001). The structural characterization is based on the application of complementary information content of X-ray scattering techniques like high-resolution X-ray diffraction (XRD), X-ray reflectivity (XRR), and X-ray diffuse scattering (XDS). One main focus of the analysis is to derive a sample model that sufficiently describes all experimental datasets. In addition, the reliability of parameters extracted by just one single method is discussed. It turned out that XRR is more sensitive to the near surface region, indicating the presence of surface roughness and density gradients that do not significantly affect the XRD pattern.

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