Chemical Stability of SC1-Cleaned Hydrogen Terminated Si(100) Surfaces

1995 ◽  
Vol 386 ◽  
Author(s):  
C. H. Bjorkman ◽  
H. Nishimura ◽  
T. Yamazaki ◽  
J. L. Alay ◽  
M. Fukuda ◽  
...  
Keyword(s):  
Chemical Stability ◽  
Photoelectron Spectroscopy ◽  
Surface Concentration ◽  
Attenuated Total Reflection ◽  
Surface Contamination ◽  
Loading Conditions ◽  
Ft Ir ◽  
Atr Spectroscopy ◽  
Water Rinsing ◽  
Water Rinse

ABSTRACTSurface contamination and chemical stability of hydrogen terminated Si(100) surfaces have been studied using Fourier Transform Infrared Attenuated Total Reflection (FT-IR-ATR) spectroscopy and X-ray Photoelectron Spectroscopy (XPS). Hydrogen terminated Si(100) is obtained by removing the chemical oxide, formed in a low-concentration-NH4OH SC1 clean, in various HF based solutions. Using standard cleaning and loading conditions, we find a direct correlation between surface roughness and the amount of adsorbed C contamination. Oxidation during water rinsing and wafer loading observed by both FT-IR-ATR and XPS indicates that dihydride terminated silicon atoms are preferentially oxidized. Optimizing the water rinse and wafer loading conditions reduces total atomic concentration of C, O, and F surface contamination from 20–30 at.% to less than 6 at.%. These clean surfaces enable XPS-identification of the Si-Hx components of the Si 2p core-level spectra as well as estimation of the relative surface concentration of Si-Hx and contamination species.

Diffusion Measurements Using FT-IR ATR Spectroscopy: Lubricant Diffusion in Polypropylene

2002 ◽  
Vol 56 (4) ◽  
pp. 509-514 ◽  
Author(s):  
Xiaohua Yi ◽  
Karen Nerbonne ◽  
John Pellegrino
Keyword(s):  
Current Model ◽  
Mineral Oil ◽  
Attenuated Total Reflection ◽  
Lubricant Layer ◽  
Polymer Interfaces ◽  
Time Resolved ◽  
Polymer Sample ◽  
Ft Ir ◽  
Atr Spectroscopy ◽  
Poly Propylene

We present an experimental method for measuring diffusion of lubricants (or any highly viscous fluid) in polymers using Fourier transform infrared (FT-IR) attenuated total reflection (ATR) spectroscopy. Unlike the conventional FT-IR ATR diffusion measurement, in which a polymer sample is sandwiched between the penetrant and an internal reflection element (IRE), in this method, a thin layer of penetrant (for example, a lubricant) is sandwiched between the IRE and the polymer sample. This allows accurate control and measurement of the thickness of the lubricant layer, which, in turn, facilitates subsequent data analysis. The diffusion is studied by monitoring the time-resolved change in absorbance of either a unique polymer or penetrant band. A feature of this new method is that it can provide an estimate of solubility, as well as an estimate of the diffusivity of the penetrant in the polymer. Using this method, we studied the diffusion of mineral oil and a commercial fluorocarbon ether lubricant (Krytox® 143AC‡) in poly(propylene) (PP) film at room temperature. The experimental data was modeled using a Fickian model with impermeable and saturated boundary conditions applied at the IRE/lubricant and lubricant/polymer interfaces, respectively. The diffusivity and solubility of mineral oil in PP were found to be 1.34 ± 0.35 (×10−10) cm2/s and 0.77 ± 0.13 (×10−2) g/g of PP, respectively. The current model was unable to quantitatively describe the diffusion of the Krytox® 143AC in the PP, possibly due to excessive swelling.

Chemical Structures of Native Oxides Formed During Wet Chemical Treatments on NH4F Treated Si(111) Surfaces

1992 ◽  
Vol 259 ◽  
Author(s):  
Takeo Hattori ◽  
Hiroki Ogawa
Keyword(s):  
Photoelectron Spectroscopy ◽  
Attenuated Total Reflection ◽  
Native Oxide ◽  
X Ray ◽  
Chemical Treatments ◽  
Chemical Structures ◽  
Native Oxides ◽  
Ft Ir ◽  
Wet Chemical ◽  
Silicon Interface

ABSTRACTChemical structures of native oxides formed during wet chemical treatments on NH4F treated Si(111) surfaces were investigated using X-ray Photoelectron Spectroscopy (XPS) and Fourier Transformed Infrared Attenuated Total Reflection(FT-IR-ATR). It was found that the amounts of Si-H bonds in native oxides and those at native oxide/silicon interface are negligibly small in the case of native oxides formed in H2SO4-H2O2-H2O solution. Based on this discovery, it was confirmed that native oxides can be characterized by the amount of Si-H bonds in native oxides. Furthermore, it was found that the combination of various wet chemical treatments with the treatment in NH4OH-H2O2-H2O solution results in the drastic decrease in the amount of Si-H bonds in native oxides.

Atr/Ft-Ir Difference Spectroscopy of Biological Matter with Microsecond Time Resolution

1996 ◽  
Vol 50 (5) ◽  
pp. 588-596 ◽  
Author(s):  
Joachim Heberle ◽  
Christian Zscherp
Keyword(s):  
Attenuated Total Reflection ◽  
High Temporal Resolution ◽  
Difference Spectroscopy ◽  
Difference Spectra ◽  
Time Resolved ◽  
Precise Control ◽  
Biological Matter ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Atr Spectroscopy

Attenuated total reflection (ATR) spectroscopy allows precise control of external parameters vital for proper functioning of biological matter. For the first time in biospectroscopy, ATR difference spectroscopy has been combined with the step-scan technique. The current setup integrates a broad frequency range (800–25,000 cm−1) with high temporal resolution (5 μs). Vibrations are detected that arise from single amino acids (<10−3 absorbance units) of the chromoprotein bacteriorhodopsin. Time-resolved ATR/FT-IR difference spectra are compared with conventional transmission spectra. The high mirror stability enables time-resolved FT-vis spectroscopy of the same sample with the same instrument. Potential applications even to non-light-absorbing biomaterial are discussed.

scholarly journals Effect of Gelation Temperature on the Molecular Structure and Physicochemical Properties of the Curdlan Matrix: Spectroscopic and Microscopic Analyses

2020 ◽  
Vol 21 (17) ◽  
pp. 6154
Author(s):  
Barbara Gieroba ◽  
Anna Sroka-Bartnicka ◽  
Paulina Kazimierczak ◽  
Grzegorz Kalisz ◽  
Izabela S. Pieta ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Surface ◽  
Attenuated Total Reflection ◽  
Force Microscopy ◽  
Surface Sensitivity ◽  
Atomic Force ◽  
Wide Range ◽  
The Matrix ◽  
Ft Ir ◽  
Ir And Raman

In order to determine the effect of different gelation temperatures (80 °C and 90 °C) on the structural arrangements in 1,3-β-d-glucan (curdlan) matrices, spectroscopic and microscopic approaches were chosen. Attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) and Raman spectroscopy are well-established techniques that enable the identification of functional groups in organic molecules based on their vibration modes. X-ray photoelectron spectroscopy (XPS) is a quantitative analytical method utilized in the surface study, which provided information about the elemental and chemical composition with high surface sensitivity. Contact angle goniometer was applied to evaluate surface wettability and surface free energy of the matrices. In turn, the surface topography characterization was obtained with the use of atomic force microscopy (AFM) and scanning electron microscopy (SEM). Described techniques may facilitate the optimization, modification, and design of manufacturing processes (such as the temperature of gelation in the case of the studied 1,3-β-d-glucan) of the organic polysaccharide matrices so as to obtain biomaterials with desired characteristics and wide range of biomedical applications, e.g., entrapment of drugs or production of biomaterials for tissue regeneration. This study shows that the 1,3-β-d-glucan polymer sample gelled at 80 °C has a distinctly different structure than the matrix gelled at 90 °C.

scholarly journals Designing Zirconium Coated Polystyrene Colloids and Application

2009 ◽  
Vol 2009 ◽  
pp. 1-6 ◽  
Author(s):  
Diana Chira ◽  
Seong S. Seo
Keyword(s):  
Zirconium Oxychloride ◽  
Nerve Agent ◽  
Attenuated Total Reflection ◽  
Practical Application ◽  
Sem Images ◽  
X Ray ◽  
Ir Studies ◽  
Ft Ir ◽  
Amine Groups ◽  
Atr Spectroscopy

A simple technique has been developed to prepare core colloids that are modified using zirconium oxychloride, based on heating a solution of core colloid composites, consisting of poly (ethylenimine) (PEI) and zirconium oxychloride. The interaction of zirconium oxychloride with the polystyrene (PS) core colloids has been investigated using Fourier transform-infrared spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM) data. FT-IR studies confirm the occurrence of amine groups present in PEI which are oxidized to carboxyl groups after the reaction. The EDX data and the SEM images confirm the presence of zirconium particles immobilized on the polystyrene surfaces. Demeton, a highly toxic nerve agent, was used due to its ability to easily bind through its organophosphate group illustrating a practical application of the PS-PEI-Zr particles. Attenuated Total Reflection (ATR) Spectroscopy was used to assess the interactions between the toxic nerve agent demeton-S and the PS-PEI-Zr particles. The results show that the presented technique for coating polystyrene core colloids with zirconium was successfully accomplished, and the newly formed particles easily bond with demeton agents through the P=O functional group.

Discrimination of Soil-Borne Fungi Using Fourier Transform Infrared Attenuated Total Reflection Spectroscopy

2008 ◽  
Vol 62 (3) ◽  
pp. 302-305 ◽  
Author(s):  
Raphael Linker ◽  
Leah Tsror(LAHKIM)
Keyword(s):  
Fourier Transform ◽  
Success Rate ◽  
Fourier Transform Infrared ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Economic Damage ◽  
Genus Level ◽  
Ft Ir ◽  
Atr Spectroscopy ◽  
Soil Borne Fungi

Fourier transform infrared (FT-IR) attenuated total reflection (ATR) spectroscopy was used to discriminate five commonly encountered soil-borne fungi that cause severe economic damage to agriculture: Colletotrichum, Fusarium, Pythium, Rhizoctonia, and Verticillium. Contrary to previous studies related to microorganism discrimination using FT-IR-ATR spectroscopy, the pathogen samples were not dried on the ATR crystal, which is a time-consuming operation. Rather, after removing some pathogen filaments from the solution using tweezers, these were placed directly on a flat ATR crystal and pressure was applied using a pressure clamp. Following water subtraction, baseline correction, and normalization of the spectra, principal component analysis was used as a data-reduction step and canonical variate analysis was used for discrimination. Discrimination was performed at the genus level and at the strain level for Colletotrichum. For discrimination between the five fungi at the genus level, the success rate for the validation samples ranged from 75% to 89%. For discrimination between the two Colletotrichum strains, the success rate was 78%. Comparison with spectra of similar fungi dried on the ATR crystal showed that both types of spectra were very similar, indicating that drying the samples on the ATR crystal is not required and can be replaced by mathematical post-processing of the spectra. For routine analyses that involve rapid screening of very large amounts of samples, this approach allows for increasing significantly the number of samples that can be analyzed daily.

Influence of BHF Treatments on Hydrogen-Terminated Si(100) Surfaces

1997 ◽  
Vol 477 ◽  
Author(s):  
T. Osada ◽  
Y. Kawazawa ◽  
S. Miyazaki ◽  
M. Hirose
Keyword(s):  
Photoelectron Spectroscopy ◽  
Treatment Time ◽  
Ionic Species ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
The Other ◽  
Reflection Spectroscopy ◽  
X Ray ◽  
Molar Ratios ◽  
Ft Ir

ABSTRACTThe hydrogen bonding features of Si(100) surfaces treated with BHF (NH4F/HF/H2O) have been studied by Fourier transform infrared attenuated total reflection spectroscopy (FT-IR-ATR). The amount of residual silicon-fluorine bonds on Si(100) surfaces has been evaluated by X-ray photoelectron spectroscopy (XPS). It is found that Si-H3 bonds appears to be preferentially removed by OH ions so as to increase the surface SiH2 and SiH bonds. On the other hand, it is likely that fluorine-containing ionic species such as HF2 might attack the backbonds of surface hydrides to produce Si-H3 and Si-F bonds. ATR spectra have shown that a BHF treated Si(100) surface in 5∼10% NH4F with molar ratios of HF/NH4F=0.37∼0.56 (pH=3.7∼4.0) at a treatment time of 5 minutes is atomically flatter than that treated in BHF containing 15∼20% NH4F. This is because the amount of residual Si-F bonds on Si(100) increases with HF2 concentration in BHF and these Si-F bonds enhance attacking of silicon backbonds of Si-F bond by OH− and HF2− ions.

scholarly journals XPS and FT-IR Characterization of Selected Synthetic Corrosion Products of Zinc Expected in Neutral Environment Containing Chloride Ions

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Juliusz Winiarski ◽  
Włodzimierz Tylus ◽  
Katarzyna Winiarska ◽  
Irena Szczygieł ◽  
Bogdan Szczygieł
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Chloride Ions ◽  
Corrosion Products ◽  
Zinc Alloy ◽  
Solid State Method ◽  
X Ray ◽  
Ft Ir ◽  
Atr Spectroscopy

ZnO, Zn(OH)2, Zn5(OH)8Cl2·H2O, ZnCO3, and Zn5(CO3)2(OH)6 synthetic powders were prepared by chemical or solid-state method. Their crystalline phase structure, thermal behavior, and morphology were examined. Characteristic infrared absorbance bands were estimated by means of FT-IR ATR spectroscopy. X-ray photoelectron spectroscopy (XPS) allowed to calculate the modified Auger parameters (α ′) thereof to 2010.2, 2009.3, 2009.4, 2009.7, and 2009.8 eV, respectively for ZnO, Zn(OH)2, Zn5(OH)8Cl2·H2O, ZnCO3, and Zn5(CO3)2(OH)6. Finally, comparison of surface composition may be crucial to evaluation of the unknown experimental spectra of corrosion products formed on the surface of zinc alloy coatings exposed in NaCl solution.

Effect of grafted poly [2-methacryloyloxyethyl phosphorylcholine (MPC)] on tribological properties of ultra-high molecular weight polyethylene (UHMWPE)

2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940056
Author(s):  
T. T. Ye ◽  
Q. Y. Deng ◽  
D. L. Ma ◽  
P. C. Li ◽  
B. Huang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Photoelectron Spectroscopy ◽  
Wear Test ◽  
Attenuated Total Reflection ◽  
Polar Groups ◽  
Pretreatment Time ◽  
Ft Ir ◽  
Good Biocompatibility ◽  
Ultra High Molecular Weight

2-methacryloyloxyethyl phosphorylcholine (MPC) polymers have good biocompatibility and hydrophilicity because the function of the phospholipid polar groups of MPC side-chain is similar to the natural articular cartilage. MPC has a potential application on surface modification of artificial joints. In this research, MPC was grafted on ultra-high molecular weight polyethylene (UHMWPE) by the photo-induced graft polymerization to form poly 2-methacryloyloxyethyl phosphorylcholine (PMPC) layer. The microstructure of PMPC layer was studied by Fourier-transform infrared (FT-IR) spectroscopy with attenuated total reflection (ATR) equipment, X-ray photoelectron spectroscopy (XPS). The surface wettability of PMPC layer was evaluated by the contact angle test. The wear resistance of MPC modified UHMWPE was evaluated by the wear test. The results show that the PMPC layer has a good lubricating effect and it can reduce the friction coefficient effectively. The benzophenone pretreatment time is an important factor in the graft stability of MPC.

Quantitative Analysis of Adsorbed Serum Albumin on Segmented Polyurethane Using FT-IR/ATR Spectroscopy

1992 ◽  
Vol 46 (11) ◽  
pp. 1644-1648 ◽  
Author(s):  
J. S. Jeon ◽  
R. P. Sperline ◽  
S. Raghavan
Keyword(s):  
Serum Albumin ◽  
Solution Concentration ◽  
Attenuated Total Reflection ◽  
Stratified Medium ◽  
Bulk Solution ◽  
Total Peak Area ◽  
Ft Ir ◽  
Adsorption Density ◽  
Flowing System ◽  
Atr Spectroscopy

FT-IR attenuated total reflection (ATR) spectroscopy was applied to quantitatively determine the extent of bovine serum albumin adsorbed onto a biomedical-grade poly(ether)urethane film deposited on a ZnSe internal reflection element (IRE). The method of adsorption density determination was based on the optical principles for a stratified medium consisting of three layers. The spectral peak area due to bulk solution was less than 1% of total peak area. The measured adsorption density of albumin in a flowing system was 3.9 μg/cm2 at a solution concentration of 4.5 g/100 mL.

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