Photo-Chemical Changes of Aluminium Films on Silicon

1988 ◽  
Vol 119 ◽  
Author(s):  
A. J. Kellock ◽  
J. S. Williams ◽  
G. L. Nyberg ◽  
J. Liesegang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Surface Oxidation ◽  
Rutherford Backscattering ◽  
Rutherford Backscattering Spectroscopy ◽  
Chemical Changes ◽  
X Ray ◽  
Surface And Interface ◽  
Photon Irradiation

AbstractX-ray Photoelectron Spectroscopy and Rutherford Backscattering Spectroscopy with channeling are employed to study surface and interface changes resulting from irradiation of thin Al films on Si-SiO2 substrates using < 6eV visible photons. Results indicati that surface oxidation and bonding rearrangements at the Al-SiO2-Si interface can take place at room temperature under photon bombardment. These changes are correlated with enhanced adhesion and modification of film etch properties which are also a result of photon irradiation.

Photon-Induced Adhesion and Chemical Changes in Aluminium Films on Silicon.

1986 ◽  
Vol 75 ◽  
Author(s):  
Andrew J. Kellock ◽  
J. Liesegang ◽  
G. L. Nyberg ◽  
J. S. Williams
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Interface Reaction ◽  
Thin Layers ◽  
Chemical Changes ◽  
X Ray ◽  
Photon Irradiation ◽  
Film Adhesion ◽  
Transmission Electron ◽  
Before And After

AbstractIn the present study, thin layers of Al (<500 Å), deposited on Si under varying vacuum and substrate-cleaning conditions, have been irradiated with various wavelength photons. The films and interfacial oxide layers have been analysed with Rutherford backscattering and channeling (RBS-C), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) techniques both before and after irradiation. Results indicate that substantial oxygen uptake, indiffusion and interface reaction can take place in some thin Al films during photon irradiation at room temperature. Such photon-induced chemical changes correlate with an increase in film adhesion.

Characterization of europium implanted LiNbO3

1993 ◽  
Vol 8 (10) ◽  
pp. 2679-2685 ◽  
Author(s):  
P. Moretti ◽  
B. Canut ◽  
S.M.M. Ramos ◽  
R. Brenier ◽  
P. Thévenard ◽  
...  
Keyword(s):  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Rutherford Backscattering ◽  
Oxidation States ◽  
Xps Spectra ◽  
X Ray ◽  
Partial Recrystallization ◽  
Lower Charge

LiNbO3 single crystals were implanted at room temperature with Eu+ ions at 70 keV with fluence ranging from 0.5 to 5 × 1016 ions · cm−2. The damage in the implanted layer has been investigated by Channeling Rutherford Backscattering (RBS-C), and the oxidation states of the cations have been determined by x-ray photoelectron spectroscopy (XPS). Following implantation, a fully amorphized layer of 60 nm is generated, even for the lowest fluence employed. Subsequent annealing in air, in the range 800–1250 K, was applied to restore tentatively the crystallinity and promote the substitutional incorporation of Eu in the crystal. Only a partial recrystallization of the damaged layer was observed. For as-implanted samples, XPS spectra clearly reveal europium in Eu2+ and Eu3+ states, and the Nb5+ ions are driven to lower charge states.

Surface Stoichiometry of CdSe Nanocrystals

1998 ◽  
Vol 536 ◽  
Author(s):  
Jason Taylor ◽  
Tadd Kippeny ◽  
Jonathan C. Bennett ◽  
Mengbing Huang ◽  
Leonard C. Feldman ◽  
...  
Keyword(s):  
High Temperature ◽  
Photoelectron Spectroscopy ◽  
Size Dependence ◽  
Intrinsic Property ◽  
Rutherford Backscattering ◽  
Rutherford Backscattering Spectroscopy ◽  
Trioctylphosphine Oxide ◽  
Cdse Nanocrystals ◽  
X Ray

AbstractRutherford backscattering spectroscopy (RBS) has been applied to determine the constitution of prototypical CdSe nanocrystals synthesized by the high temperature pyrolysis of organometallics in trioctylphosphine oxide (TOPO). The diameter of the nanocrystals was varied from 22 Å to 58 Å. For all nanocrystal sizes the nanocrystals are Cd rich with an average Cd:Se ratio of 1.2 ± 0.1. The Cd:Se stoichiometery is independent of the starting Cd:Se ratio used for nanocrystal preparation, indicating the excess Cd is not associated with the initial abundance but is an intrinsic property of nanocrystals prepared by this method. The size dependence of excess Cd indicates the extra Cd is on the surface of the crystallite. The coverage of the surface passivating TOPO ligands has also been determined and is larger than reported in previous X-ray photoelectron spectroscopy (XPS) studies of Bowen Katari et al. The origin and structural implications of non-stoichoimetric Cd are discussed.

scholarly journals The Initial Stage in Oxidation of ZrNiSn (Half Heusler) Alloy by Oxygen

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1509 ◽  
Author(s):  
Oshrat Appel ◽  
Gil Breuer ◽  
Shai Cohen ◽  
Ofer Beeri ◽  
Theodora Kyratsi ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Surface Composition ◽  
Surface Oxidation ◽  
Oxide Interface ◽  
X Ray ◽  
Working Temperature ◽  
Initial Stage ◽  
Semiconducting Alloys

The MNiSn (M = Ti; Zr; Hf); half-Heusler semiconducting alloys have a high potential for use as n-type thermoelectric materials at elevated temperatures (~1000 K). The alloys’ durability is crucial for their commercial handling and use, and therefore it is required to characterize their surface oxidation behavior and stability at the working temperature. X-ray photoelectron spectroscopy was utilized to study the surface composition and oxidation of the ZrNiSn alloy at room and elevated temperatures. It was found that during heating in a vacuum, Sn segregates to the surface in order to reduce the surface energy. Exposing the alloy to oxygen resulted mainly in the oxidation of the zirconium to ZrO2, as well as some minor oxidation of Sn. At room temperature, the oxidation to ZrO2 was accompanied by the formation of a thin ZrO layer at the metal-oxide interface. In contrast to TiNiSn, where most of the oxide was formed on the surface due to oxygen-enhanced segregation of Ti, and in the case of ZrNiSn, the formed oxide layer was thinner. Part of the oxide is formed due to Zr segregation to the surface, and in part due to oxygen dissolved into the alloy.

Surface oxidation of a quasicrystalline Al–Cu–Fe alloy:No effect of surface orientation and grain boundaries onthe final state

1999 ◽  
Vol 14 (8) ◽  
pp. 3185-3188 ◽  
Author(s):  
P. J. Pinhero ◽  
J. W. Anderegg ◽  
D. J. Sordelet ◽  
T. A. Lograsso ◽  
D. W. Delaney ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Surface Oxidation ◽  
Surface Orientation ◽  
Final State ◽  
Random Surface ◽  
X Ray ◽  
Significant Difference ◽  
Single Grain ◽  
Effect Of Surface

We have used x-ray photoelectron spectroscopy and Auger electron spectroscopy to examine the characteristics of oxides on two types of quasicrystalline Al–Cu–Fe samples. One type was formed by consolidation of powders, resulting in multiple grains with random surface orientations. The other was a single grain, oriented to expose a fivefold surface. Both were oxidized to saturation in a variety of environments at room temperature. We measured the elemental constituents that oxidized, the extent of oxygen-induced Al segregation, and the depth of the oxide. Under the conditions of our experiments, there was little, if any, significant difference between the two types of samples. Hence, surface orientation and bulk microstructure played little or no role on the final state of the oxide under these conditions.

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