Silicon oxide films

Silicon oxide films contain a thin surface layer of silicon oxide, a glass-like material that acts to improve barrier in much the same way as the aluminum in metallized film. Because the layer is extremely thin, the mechanical properties of the resulting material are essentially the same as the uncoated film. The SiO layer may impart a slight yellowish color to the film, but, in contrast to metallized materials. 

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Chemical Vapor Deposition- Deposition of silicon oxide films is accomplished by CVD equipment. Either plasma CVD or ozone oxidation is used. Blanket tungsten films are also deposited by CVD equipment to create contact and via plugs. Polysilicon and silicon nitride films are deposited in hot-wall furnaces. TiN diffusion barrier films are deposited by either sputtering or CVD, the latter giving superior step coverage. 

Oscillations have been observed in chemical as well as electrochemical systems [Frl, Fi3, Wol]. Such oscillatory phenomena usually originate from a multivariable system with extremely nonlinear kinetic relationships and complicated coupling mechanisms [Fr4], Current oscillations at silicon electrodes under potentio-static conditions in HF were already reported in one of the first electrochemical studies of silicon electrodes [Tul] and ascribed to the presence of a thin anodic silicon oxide film. In contrast to the case of anodic oxidation in HF-free electrolytes where the oscillations become damped after a few periods, the oscillations in aqueous HF can be stable over hours. Several groups have studied this phenomenon since this early work, and a common understanding of its basic origin has emerged, but details of the oscillation process are still controversial. 

R.J. Kee, W. Yang, N. Sullivan, A.M. Dean, A. Zojaji, M. Hall, and M. Williams. The Formation of Ultra-Thin Silicon-Oxide Films Using H2-N2O Mixtures. Proc. Combust. Inst., 29 In press, 2002. 

It appears that di-coordinated oxygen configurations such as backbond and dimer-bridge are the most stable forms and play a significant role in the initial growth of silicon oxide film. 

Lim DS, Ahn JW, Park HS, Shin JH. The effect of Ce02 abrasive size on dishing and step height reduction of silicon oxide film in STI-CMP. Surf Coat Technol 2005 5-6 1751-1754. 

Sawada, M., Oobayashi, S., Yamaguchi, K., Takemura, H., Nakamura, M., Momose, K., and Saka, H., Characteristics of light emission lifetime of electroluminescent phosphor encapsulated by titanium-silicon-oxide film, Jpn. J. Appl. Phys., 41, 3885, 2002. 

S. Yamazaki and K. Tsutsumi, Synthesis of an A-type zeolite membrane on silicon oxide film-silicon, quartz plate and quartz fiber filter, Microporous Materials 4 205 (1995). 

Silicon oxide films were etched in a buffer etchant (HF NH4F H20= 1 10 15) and p-etchant (HF HNO3 H2O=l l 30) and also by plasma exposure in a UVN-71RZS system at a pressure of 9x10" Pa, using Freon 113 the reactant g. ... 

Figure 2. Etching rate as a function of time for silicon oxide films (1,2) plasma etching, (3, 3) p-etchant, (5, 6) buffer etchant oxidation in (1, 3, 5) dry and (2,4, 6) humid oxygen.

The present data on the effect of the preparation procedure and particle size on the oxidation rate of silicon micro- and nanopowders and the physicochemical properties of the silicon oxide films produced fi-om the powders shed light on the origin of the irreproducibility of the published data. Comparison of the oxidation behavior of silicon powders with that of single-crystal Si indicates that these materials are sensitive to the oxidation conditions. Silicon nanopowders have the... 

Silicon oxide films can be produced by different methods, such as thermal oxidation or chemical vapor deposition, and have a diverse range of stractures and properties. Characteristically, different types of oxide have distinct densities, for... 

Silicon oxide films can be deposited by the pyrolytic oxidation of a silane or alkoxysilane in a chemical vapor deposition (CVD) system. ° In a process using silane... 

Conductive anodic silicon oxide films can be produced by doping a submonolayer of platinum in the oxide. ° The platinum is deposited on the silicon surface gal-vanostatically from 5% H2PtCl6 for a thickness from 0.002 to 2.5 monolayers. The silicon is then anodized in 0.2 M H2SO4 under illumination followed by a heat treatment. The Pt is present in the film at 0.25 (at Si/Si02) to 0.03 (SiOa/solution) atom % and either as Pt or as PtO with an energy level close to the n-Si valence band edge. 

The electroless deposition of metals on a silicon surface in solutions is a corrosion process with a simultaneous metal deposition and oxidation/dissolution of silicon. The rate of deposition is determined by the reduction kinetics of the metals and by the anodic dissolution kinetics of silicon. The deposition process is complicated not only by the coupled anodic and cathodic reactions but also by the fact that as deposition proceeds, the effective surface areas for the anodic and cathodic reactions change. This is due to the gradual coverage of the metal deposits on the surface and may also be due to the formation of a silicon oxide film which passivates the surface. In addition, the metal deposits can act as either a catalyst or an inhibitor for hydrogen evolution. Furthermore, the dissolution of silicon may significantly change the surface morphology. 

T. Homma, Properties of fluorinated silicon oxide films formed using fluorotriethoxysilane for interlayer dielectrics in multilevel interconnections, J. Electrochem. Soc. 143, 1084, 1996. 

P. Schmuki, H. Bohni, and J. A. Bardwell, In-situ characterization of anodic silicon oxide films by AC impedance measurements, J. Electrochem. Soc. 142, 1705, 1995. 

G. Mende, H. Flietner, and M. Deutscher, Optimization of anodic silicon oxide films for low temperature passivation of silicon surfaces, J. Electrochem. Soc. 140, 188, 1993. 

G. Mende and E. Hensel, The electrophysical properties of anodically grown silicon oxide film. Thin Solid Films 168, 51, 1989. 

B. Agius, M. Froment, and S. R. Rochet, Oxygen transport studied by labeling in thin thermal silicon oxide films in connection with their structural characteristics, in Passivity of Metals and Semiconductors, M. Froment (ed.), p. 453, Elsevier, Amsterdam, 1983. 

Vahlas C, Davazoglou D, Vamvacas VE, de Parseval P (1997) Thermochemistry and composition of LPC VD silicon oxides films grown from NH3/TEOS mixtures. In Allendorf MD, Bernard C (eds) Proceedings of the 14th international conference on chemical vapor deposition/Jointly held with the Euro CVD-11. Electrochemical Society, Pennington, NJ, ppl 175-1182... 

Xie et al. [49] investigated the tribological behaviors of different ILs as lubricants for tribo-pairs (low-temperature silicon oxide film/SijN ball, polysilicon Si film/ SijN ball, and silicon nitride (SijN ) film/SijN ball) by varying the applied load and the sliding velocity. The ILs lubricants showed the best lubricating properties for the three tribo-pairs at the intermediate load of 150 g. 

PECVD silicon oxide films are used as a dielectric material for isolation of aluminum interconnections due to the low deposition temperature required (Al, m.p. =... 

The introduction of QDs into aqueous media is usually accompanied by drastic decreases in the luminescence yields of the QDs. This effect presumably originates from the reaction of surface states with water, a process that yields surface traps for the conduction-band electrons [63]. As biorecognition events or biocat-alytic transformations require aqueous environments for their reaction medium, it is imperative to preserve the luminescence properties of QDs in aqueous systems. Methods to stabilize the fluorescence properties of semiconductor QDs in aqueous media (Figure 6.2) have included surface passivation with protective layers, such as proteins [64, 65], as well as the coating of QDs with protective silicon oxide films [66, 67] or polymer films [43, 68, 69). Alternatively, they can be coated with amphiphilic polymers, which have both a hydrophobic side chain that interacts with the organic capping layer of the QDs and a hydrophilic component, such as a poly(ethylene glycol) (PEG) backbone, for water solubility [70, 71). Such water-soluble QDs may retain up to 55% of their quantum yields upon transfer to an aqueous medium. 

Native silicon oxide films (1.5 nm) were formed by dipping Si in solutions of (a) ultrapure water with ozone O3, (b) NH4OH-H2O2-H2O, and (c) H2O2-H2O and analyzed by ATR [86]. The chemical oxides aU demonstrate some degree of imperfection, as indicated by the frequency of the vlo band (1214, 1213, and 1173 cm for films from solutions a, b, and c, respectively) (Fig. 5.10). The... 

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