Surface Chemical Studies of Oxides and Nitrides

1984 ◽  
Vol 40 ◽  
Author(s):  
Carlo G. Pantano

AbstractThe application of surface analysis techniques for the study of fundamental surface and thin film phenomena is described. The topics covered relate to the processing and fabrication of electronic packages and include: evaporation/condensation during the thermal processing of glasses, hydration of glass surfaces and thin films, nitridation of silica films, diffusion behavior in oxides at low temperature, and impurity segregation in thin films. A wide variety of surface analytical methods are exemplified including Auger electron spectroscopy (AES), ion-scattering spectroscopy (ISS), nuclear reaction analysis (NRA), secondary-ion mass spectroscopy (SIMS) and x-ray photoelectron spectroscopy (XPS).

1984 ◽  
Vol 32 ◽  
Author(s):  
Carlo G. Pantano ◽  
C. A. Houser ◽  
R. K. Brow

ABSTRACTThe application of surface analysis techniques to the characterization of sol/gel surfaces and thin films is described. Secondary-ion mass spectroscopy (SIMS), x-ray photoelectron spectroscopy (XPS) and sputter-induced photon spectroscopy (SIPS) are used to measure the composition of multicomponent silicate films, the relative water content of alumina films, the nitrogen content of ammonia treated silica films, and the depth profiles for films on black chrome. The determination of chemical structure using XPS and SIMS is also discussed. Finally, a brief introduction to temperature-programmed desorption (TPD) and its potential for studying surface chemical reactions, in situ, is presented.


2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
K. Zakrzewska

This paper treats a problem of nonstoichiometry inTiO2−ythin films deposited by reactive sputtering at controlled sputtering rates. Ion beam techniques, Rutherford backscattering (RBS), and nuclear reaction analysis (NRA) along with X-ray photoelectron spectroscopy have been applied to determine a deviation from stoichiometryyin the bulk and at the surface ofTiO2−ylayers. The critical review of these experimental methods is given. Defect structure responsible for the electrical resistivity of rutileTiO2is discussed.


1996 ◽  
Vol 440 ◽  
Author(s):  
Hisashi Shigetani ◽  
Kazuyoshi Kobayashi ◽  
Masayuki Fujimoto ◽  
Wataru Sugimura ◽  
Yoshio Matsui ◽  
...  

AbstractWe studied a lattice distortion and relaxation of BaTiO3(BT) thin films grown on SrTiO3 (001) substrates(ST) by a molecular beam epitaxy method using an oxygen radical source RT were prepared by alternately deposition of BaO and TiO2 layers, and the structure of the thin films was evaluated by X-ray diffraction, reflection high energy electron diffraction, transmission electron microscopy, atomic force microscopy, coaxial impact collision ion scattering spectroscopy and X-ray photoelectron spectroscopy The lattice constants of the films varied with distance from the interface of BT and ST It was found that lattice distortion and relaxation of BT On the other hand, the surface analysis indicated that adsorbed oxygen was enriched on the BaO-terminated surface in comparison with the TiO2-terminated surface Then we proposed new mechanism of BT thin film growth with adsorbed oxygen.


NANO ◽  
2009 ◽  
Vol 04 (02) ◽  
pp. 99-106 ◽  
Author(s):  
LI WEI ◽  
BO WANG ◽  
DAPENG LIU ◽  
LAIN-JONG LI ◽  
YANHUI YANG ◽  
...  

A facile method was developed for in situ formation of Co nanoclusters in sol–gel silica thin films spin-coated on Si wafers. The size and density of Co nanoclusters can be controlled by spin-coating speeds, annealing methods, reduction temperatures under H 2, and metal precursor concentrations in tetraethylorthosilicate solutions. The optimized preparation condition, spin-coating speed of 9000 rpm, annealing at 500°C in air followed by reduction at 800°C in H 2, resulted in silica films as thin as 60 nm and Co nanoclusters with a mean diameter of 1.5 nm. Morphological and chemical characteristics of thin films and nanoclusters were studied by atomic force microscopy and X-ray photoelectron spectroscopy, respectively. Subsequently, these Co nanoclusters were successfully used to grow SWCNTs by CO decomposition. Film containing Co monometallic clusters produced SWCNTs of 1.3 nm in diameter, whereas film having Co/Mo bimetallic clusters produced SWCNTs of 0.9 nm. This sol–gel approach allowed not only easy catalyst patterning on a thin film but also a fine-tuning of SWCNT properties, e.g., diameter.


Author(s):  
J. F. Moulder ◽  
J. M. Burkstrand ◽  
C. D. Wagner

As the dimensions of microelectronic devices continue to shrink, the use of surface sensitive analysis techniques to characterize thin film structures continues to grow. These techniques including: ESCA or XPS (X-ray photoelectron spectroscopy), AES (Auger electron spectroscopy), SIMS (secondary ion mass spectroscopy) and ISS (ion scattering spectroscopy) are now routinely being used to study a wide variety of material and process related problems.ESCA, which has become a standard analytical tool in the chemical industry, has not been utilized in the microelectronic industry to the extent that AES and SIMS have, even though it has the potential to provide more chemical state and structural information than other surface analysis techniques.ESCA like the other surface analysis techniques analyzes the outermost atomic layers of a solid surface (typically 5 to 50 Å in depth). A low energy X-ray source (Mg 1253.6 eV or Al 1486.7 eV) is used to bombard the sample causing electrons to be ejected from it. These photo-electrons are collected and analyzed to determine their kinetic energy.


2009 ◽  
Vol 24 (8) ◽  
pp. 2520-2527 ◽  
Author(s):  
Yonghao Lu ◽  
Junping Wang ◽  
Yaogen Shen ◽  
Dongbai Sun

A series of Ti-B-C-N thin films were deposited on Si (100) at 500 °C by incorporation of different amounts of N into Ti-B-C using reactive unbalanced dc magnetron sputtering in an Ar-N2 gas mixture. The effect of N content on phase configuration, nanostructure evolution, and mechanical behaviors was studied by x-ray diffraction, x-ray photoelectron spectroscopy, Raman spectroscopy, high-resolution transmission electron microscopy, and microindentation. It was found that the pure Ti-B-C was two-phased quasi-amorphous thin films comprising TiCx and TiB2. Incorporation of a small amount of N not only dissolved into TiCx but also promoted growth of TiCx nano-grains. As a result, nanocomposite thin films of nanocrystalline (nc-) TiCx(Ny) (x + y < 1) embedded into amorphous (a-) TiB2 were observed until nitrogen fully filled all carbon vacancy lattice (at that time x + y = 1). Additional increase of N content promoted formation of a-BN at the cost of TiB2, which produced nanocomposite thin films of nc-Ti(Cx,N1-x) embedded into a-(TiB2, BN). Formation of BN also decreased nanocrystalline size. Both microhardness and elastic modulus values were increased with an increase of N content and got their maximums at nanocomposite thin films consisting of nc-Ti(Cx,N1-x) and a-TiB2. Both values were decreased after formation of BN. Residual compressive stress value was successively decreased with an increase of N content. Enhancement of hardness was attributed to formation of nanocomposite structure and solid solution hardening.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 510
Author(s):  
Yongqiang Pan ◽  
Huan Liu ◽  
Zhuoman Wang ◽  
Jinmei Jia ◽  
Jijie Zhao

SiO2 thin films are deposited by radio frequency (RF) plasma-enhanced chemical vapor deposition (PECVD) technique using SiH4 and N2O as precursor gases. The stoichiometry of SiO2 thin films is determined by the X-ray photoelectron spectroscopy (XPS), and the optical constant n and k are obtained by using variable angle spectroscopic ellipsometer (VASE) in the spectral range 380–1600 nm. The refractive index and extinction coefficient of the deposited SiO2 thin films at 500 nm are 1.464 and 0.0069, respectively. The deposition rate of SiO2 thin films is controlled by changing the reaction pressure. The effects of deposition rate, film thickness, and microstructure size on the conformality of SiO2 thin films are studied. The conformality of SiO2 thin films increases from 0.68 to 0.91, with the increase of deposition rate of the SiO2 thin film from 20.84 to 41.92 nm/min. The conformality of SiO2 thin films decreases with the increase of film thickness, and the higher the step height, the smaller the conformality of SiO2 thin films.


Author(s):  
Tianlei Ma ◽  
Marek Nikiel ◽  
Andrew G. Thomas ◽  
Mohamed Missous ◽  
David J. Lewis

AbstractIn this report, we prepared transparent and conducting undoped and molybdenum-doped tin oxide (Mo–SnO2) thin films by aerosol-assisted chemical vapour deposition (AACVD). The relationship between the precursor concentration in the feed and in the resulting films was studied by energy-dispersive X-ray spectroscopy, suggesting that the efficiency of doping is quantitative and that this method could potentially impart exquisite control over dopant levels. All SnO2 films were in tetragonal structure as confirmed by powder X-ray diffraction measurements. X-ray photoelectron spectroscopy characterisation indicated for the first time that Mo ions were in mixed valence states of Mo(VI) and Mo(V) on the surface. Incorporation of Mo6+ resulted in the lowest resistivity of $$7.3 \times 10^{{ - 3}} \Omega \,{\text{cm}}$$ 7.3 × 10 - 3 Ω cm , compared to pure SnO2 films with resistivities of $$4.3\left( 0 \right) \times 10^{{ - 2}} \Omega \,{\text{cm}}$$ 4.3 0 × 10 - 2 Ω cm . Meanwhile, a high transmittance of 83% in the visible light range was also acquired. This work presents a comprehensive investigation into impact of Mo doping on SnO2 films synthesised by AACVD for the first time and establishes the potential for scalable deposition of SnO2:Mo thin films in TCO manufacturing. Graphical abstract


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 478
Author(s):  
Wan Mohd Ebtisyam Mustaqim Mohd Daniyal ◽  
Yap Wing Fen ◽  
Silvan Saleviter ◽  
Narong Chanlek ◽  
Hideki Nakajima ◽  
...  

In this study, X-ray photoelectron spectroscopy (XPS) was used to study chitosan–graphene oxide (chitosan–GO) incorporated with 4-(2-pyridylazo)resorcinol (PAR) and cadmium sulfide quantum dot (CdS QD) composite thin films for the potential optical sensing of cobalt ions (Co2+). From the XPS results, it was confirmed that carbon, oxygen, and nitrogen elements existed on the PAR–chitosan–GO thin film, while for CdS QD–chitosan–GO, the existence of carbon, oxygen, cadmium, nitrogen, and sulfur were confirmed. Further deconvolution of each element using the Gaussian–Lorentzian curve fitting program revealed the sub-peak component of each element and hence the corresponding functional group was identified. Next, investigation using surface plasmon resonance (SPR) optical sensor proved that both chitosan–GO-based thin films were able to detect Co2+ as low as 0.01 ppm for both composite thin films, while the PAR had the higher binding affinity. The interaction of the Co2+ with the thin films was characterized again using XPS to confirm the functional group involved during the reaction. The XPS results proved that primary amino in the PAR–chitosan–GO thin film contributed more important role for the reaction with Co2+, as in agreement with the SPR results.


1992 ◽  
Vol 270 ◽  
Author(s):  
Haojie Yuan ◽  
R. Stanley Williams

ABSTRACTThin films of pure germanium-carbon alloys (GexC1−x with x ≈ 0.0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) have been grown on Si(100) and A12O3 (0001) substrates by pulsed laser ablation in a high vacuum chamber. The films were analyzed by x-ray θ-2θ diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), conductivity measurements and optical absorption spectroscopy. The analyses of these new materials showed that films of all compositions were amorphous, free of contamination and uniform in composition. By changing the film composition, the optical band gap of these semiconducting films was varied from 0.00eV to 0.85eV for x = 0.0 to 1.0 respectively. According to the AES results, the carbon atoms in the Ge-C alloy thin film samples has a bonding configuration that is a mixture of sp2 and sp3 hybridizations.


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