Deposition amorphous

Solution Deposition of Thin Films. Chemical methods of preparation may also be used for the fabrication of ceramic thin films (qv). MetaHo-organic precursors, notably metal alkoxides (see Alkoxides, metal) and metal carboxylates, are most frequently used for film preparation by sol-gel or metallo-organic decomposition (MOD) solution deposition processes (see Sol-GEL technology). These methods involve dissolution of the precursors in a mutual solvent control of solution characteristics such as viscosity and concentration, film deposition by spin-casting or dip-coating, and heat treatment to remove volatile organic species and induce crystaHhation of the as-deposited amorphous film into the desired stmcture. 

More recently, simulation studies focused on surface melting [198] and on the molecular-scale growth kinetics and its anisotropy at ice-water interfaces [199-204]. Essmann and Geiger [202] compared the simulated structure of vapor-deposited amorphous ice with neutron scattering data and found that the simulated structure is between the structures of high and low density amorphous ice. Nada and Furukawa [204] observed different growth mechanisms for different surfaces, namely layer-by-layer growth kinetics for the basal face and what the authors call a collected-molecule process for the prismatic system. 

Vaporous silica, present as silicic acid and silicate ion Crystalline silica deposits Amorphous silica deposits... 

McCuUoch, D. G. and Merchant, A. R., The Effect of Annealing on the Structure of Cathodic Arc Deposited Amorphous Carbon Nitride Films, Thin Solid Films, Vol. 290, 1996, pp. 99-102. 

Probe measurements in silane discharges have been reported [296,297]. Apparently, no difficulties were experienced, as the deposited amorphous silicon layer on the tip was sufficiently photoconductive. For typical silane discharge conditions values for are found to be between 2 and 2.5 eV. Electron densities are around 1 x 10 cm - [296]. Probe measurement in the ASTER system failed due to strong distortions of the probe current, even after following cleaning procedures. 

Growth, Structure, and Properties of Plasma-Deposited Amorphous Hydrogenated Carbon-Nitrogen Films... 

Growth, Structure, and Properties of Plasma-Deposited Amorphous Hydrogenated Carbon-Nitrogen Films D. F. Franceschini, Institute de FIsica, Uni-versidade Federal Fluminense, Avenida Litoranea s/n, Niteroi, RJ, 24210-340, Brazil... 

Armaou and Christofides (1999) present a two-electrode design for the deposition of 500-A films on an 8-cm wafer, which sits on top of the lower electrode, as shown in Fig. 10.4-2. The reactor is fed with 10% SiEE (silane) in He at 1 torr through a showerhead. An RF power source, at 13.56 MHz frequency, is used to generate the plasma, which is transported by convection and diffusion to the surface of the wafer where reaction occurs to deposit amorphous silicon. Electrical heating elements are positioned below the wafer and along the walls to achieve a uniform temperature of the plasma and wafer at 500 K. 

In addition the films were amorphous, but this result indicates that the activation energy of the deposition may be lowered significantly when amide precursors are used. The reason is facile transamination reactions. In this sense, the amide [Ga(NMe2)3]2 is not a true SMP for GaN but a good choice for depositing amorphous GaN at very low temperatures. 

The vapour deposition method is widely used to obtain amorphous solids. In this technique, atoms, molecules or ions of the substance (in dilute vapour phase) are deposited on to a substrate maintained at a low temperature. Most vapour-deposited amorphous materials crystallize on heating, but some of them exhibit an intervening second-order transition (akin to the glass transition). Amorphous solid water and methanol show such transitions. The structural features of vapour-deposited amorphous solids are comparable to those of glasses of the same materials prepared by melt-quenching. 

Osenbach, J. W. Sodium diffusion in plasma-deposited amorphous oxygen-doped silicon-nitride (alpha-SiON H) films. Journal of Apphed Physics 63, 4494—4500 (1988). 

The molar volumes of Si and quartz, the densest form of SiC>2, are 12.1 and 22.8 cm3 mol-1, respectively deposited amorphous silica will have an even larger molar volume. 

It was pointed out earlier that photosensitivity may be realized not only by the inclusion of dyes in a polymer matrix, but also by means of multilayered system production. For TPA dispersed in a polycarbonate, sensitized by a thin layer of vacuum-deposited amorphous selenium, the quantum yield was equal to 0.7 at the electric field strength 6 x 10s V cm-1 [308]. The photoinjection efficiency of holes into polymer was equal to the efficiency in pure selenium. The spectra of the quantum efficiency is shown in Fig. 54. 

To deposit amorphous silica at room temperature saturation concentration of about 100 to 150 ppm dissolved silica must be reached138-140. These fluctuations are due to slight pH effects on solubility (Fig. 16). 

When we consider silicon films, on the other hand, the nature of the solid deposit is crucial to the behavior of the film. Depending on deposition conditions, we can deposit amorphous, polycrystalline, or single crystal films. As was noted in Chapter 1, the morphology of polycrystalline films can be complex. In the present section, we will review some aspects of polysilicon (poly) thin films deposited by CVD. The final section of this chapter will be devoted to epitaxial silicon thin films. 

These authors found that it was possible to deposit amorphous films whose Ta concentration ranged from 10 to 80 mol % by changing the reactive gas mix. Another feature of the films was that under certain conditions they contained substantial quantities of chlorine and hydrogen. Also, they did not adhere to either silicon or silicon dioxide after annealing (argon atmosphere for 1 hour at 900°C). When the substrates were dry etched in an HCI plasma for 2 minutes, they adhered to the substrate even after annealing. Since this etch removed about 50 A, it appears that the native oxide on the silicon and/or some other surface impurities on both the silicon and silicon dioxide were causing the lack of adhesion. 

I wish to thank J. Dresner and A. Catalano for supplying the deposited amorphous silicon and R. D Aiello, who oversaw the fabrication of the cells whose performance data were given in this paper. I wish to thank R. Crandall for some helpful discussions. I also wish to thank... 

Janai and Moser (1982) have used chemical-vapor-deposited amorphous silicon films that were deposited at 600°C on silica (fused quartz) substrates. Information was recorded in films with thickness d between 2500 and 5000 A by irradiation with a ruby laser pulse of 50 nsec duration and an energy density ranging from 0.4 to 1.5 J cm-2. The upper energy limit is known to be above the threshold for laser melting in a-Si (Baeri et al., 1980). To determine the optical transmission density difference... 

Figure 20 The spectral dependencies of the photogeneration efficiencies of vapor-deposited amorphous (lower curve) and poly crystalline (upper curve) layers of PECI. The efficiencies were computed on an incident photon basis.

Yamada-Takamura, Y. et al.. Hydrogen permeation barrier performance characterization of vapor deposited amorphous aluminum oxide films using coloration of tungsten oxide. Surface and Coatings Technology, 153, 114 (2002). 

Rather than investigating hot spots by removing molecules from a surface, Chen et al. were able to deposit amorphous carbonaceous nanoparticles into a localized hot spot using a modified electron-beam-induced deposition method (EBID) [120]. The carbon nanoparticles were deposited within a nanoslit cavity structure which was coated with gold to create a SERS active surface where hot spots exist [121]. 

Metallic nanopartides were deposited on ceramic and polymeric partides using ultrasound radiation. A few papers report also on the deposition of nanomaterials produced sonochemically on flat surfaces. Our attention will be devoted to spheres. In a typical reaction, commerdally available spheres of ceramic materials or polymers were introduced into a sonication bath and sonicated with the precursor of the metallic nanopartides. In the first report Ramesh et al. [43] employed the Sto-ber method [44] for the preparation of 250 nm silica spheres. These spheres were introduced into a sonication bath containing a decalin solution of Ni(CO)4. The as-deposited amorphous clusters transform to polyciystalline, nanophasic, fee nickel on heating in an inert atmosphere of argon at a temperature of 400 °C. Nitrogen adsorption measurements showed that the amorphous nickel with a high surface area undergoes a loss in surface area on crystallization. 

SiO. flame hydrolysis deposition, amorphous 0-001-0.1 mol dm NaCl authors ... 

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