Oxide films electrical properties

R.B.H. Tahar, T. Ban, Y. Ohya, and Y. Takahashi, Tin doped indium oxide thin films electrical properties, J. Appl. Phys., 83 2631-2645, 1998. 

Tahar, R. et al. 1998b. Tin doped indium oxide thin films Electrical properties. Journal of Applied Physics 83 2631. 

Shanthi E, Dutta V, Baneqee A and Chopra K L 1980 Electrical and optical properties of undoped and antimony-doped tin oxide films J. Appi. Rhys. 51 6243-51... 

Diffusion. Another technique for modifying the electrical properties of siUcon and siUcon-based films involves introducing small amounts of elements having differing electrical compositions, dopants, into substrate layers. Diffusion is commonly used. There are three ways dopants can be diffused into a substrate film (/) the surface can be exposed to a chemical vapor of the dopant at high temperatures, or (2) a doped-oxide, or (J) an ion-implanted layer can be used. Ion implantation is increasingly becoming the method of choice as the miniaturization of ICs advances. However, diffusion is used in... 

Niobium is used as a substrate for platinum in impressed-current cathodic protection anodes because of its high anodic breakdown potential (100 V in seawater), good mechanical properties, good electrical conductivity, and the formation of an adherent passive oxide film when it is anodized. Other uses for niobium metal are in vacuum tubes, high pressure sodium vapor lamps, and in the manufacture of catalysts. 

It is somewhat less corrosion resistant than tantalum, and like tantalum suffers from hydrogen embrittlement if it is made cathodic by a galvanic couple or an external e.m.f., or is exposed to hot hydrogen gas. The metal anodises in acid electrolytes to form an anodic oxide film which has a high dielectric constant, and a high anodic breakdown potential. This latter property coupled with good electrical conductivity has led to the use of niobium as a substrate for platinum-group metals in impressed-current cathodic-protection anodes. 

These facts are different demonstrations of the same event degradation reactions occur simultaneously with electropolymerization.49-59 These reactions had also been called overoxidation in the literature. The concept is well established in polymer science and consists of those reactions between the pristine polymer and the ambient that promote a deterioration of the original polymeric properties. The electrochemical consequence of a strong degradation is a passivation of the film through a decrease in the electrical conductivity that allows a lower current flow at the same potential than the pristine and nondegraded polymer film did. Passivation is also a well-established concept in the electrochemistry of oxide films or electropainting. 

To dissociate molecules in an adsorbed layer of oxide, a spillover (photospillover) phenomenon can be used with prior activation of the surface of zinc oxide by particles (clusters) of Pt, Pd, Ni, etc. In the course of adsorption of molecular gases (especially H2, O2) or more complex molecules these particles emit (generate) active particles on the surface of substrate [12], which are capable, as we have already noted, to affect considerably the impurity conductivity even at minor concentrations. Thus, the semiconductor oxide activated by cluster particles of transition metals plays a double role of both activator and analyzer (sensor). The latter conclusion is proved by a large number of papers discussed in detail in review [13]. The papers cited maintain that the particles formed during the process of activation are fairly active as to their influence on the electrical properties of sensors made of semiconductor oxides in the form of thin sintered films. 

If the above comparison of the properties of metal atoms with those of hydrogen deposited on the surface of a solid body (semiconductor) is correct, the effect of their adsorption on electric properties of semiconductor oxide films will be similar to features accompanying adsorption of hydrogen atoms. The atoms of hydrogen are very mobile and, in contrast to metal atoms, are capable of surface recombination resulting in formation of saturated molecules with strong covalent bond. 

The above results on detection of trace concentrations of oxygen by sine oxide films (and titanium oxide films, to a lesser degree), as well as the results on detection of alkyl radicals, which are acceptors of semiconductor electrons, show that the behaviour and electric properties of... 

Metal oxides. Noble metals are covered with a surface oxide film in a broad range of potentials. This is still more accentuated for common metals, and other materials of interest for electrode preparation, such as semiconductors and carbon. Since the electrochemical charge transfer reactions mostly occur at the surface oxide rather than at the pure surface, the study of electrical and electrochemical properties of oxides deserves special attention. 

T. Nagamoto, Y. Maruta, and O. Omoto, Electrical and optical properties of vacuum-evaporated indium-tin oxide films with high electron mobility, Thin Solid Films, 192 17-25 (1990). 

S. Honda, M. Watamori, and K. Oura, The effects of oxygen content on electrical and optical properties of indium tin oxide films fabricated by reactive sputtering, Thin Solid Films, 281-282 206-208, 1996. 

W.G. Haines and H.R. Bube, Effects of heat treatment on the optical and electrical properties of indium-tin oxide films, J. Appl. Phys., 49 304—307, 1978. 

Recently, much attention has focused on amorphous tantalum oxide (aTaOJ films for DRAM applications. This material has a higher FOM than SiO, with e23, Ebi4 MV/cm, FOM8.1 pC/cm2, and is of particular interest for embedded DRAM applications, for the reasons mentioned above in the context of aZTT films. State-of-the-art films are believed to have adequate electrical properties, at least for present... 

Although the literature on electrodeposited electroactive and passivating polymers is vast, surprisingly few studies exist on the solid-state electrical properties of such films, with a focus on systems derived from phenolic monomers, - and apparently none exist on the use of such films as solid polymer electrolytes. To characterize the nature of ultrathin electrodeposited polymers as dielectrics and electrolytes, solid-state electrical measurements are made by electrodeposition of pofy(phenylene oxide) and related polymers onto planar ITO or Au substrates and then using a two-electrode configuration with a soft ohmic contact as the top electrode (see Figure 27). Both dc and ac measurements are taken to determine the electrical and ionic conductivities and the breakdown voltage of the film. 

The fabrication process of vanadium oxide (VO2) has also been studied using RBS/C. Since optieal and electrical properties of VO2 are dramatically changed at 68°C due to phase transition, VO2 is regarded as one of the candidates for thermally activated electronic or optical switching devices for optieal fibers or sensors. To obtain the desired properties, the development of the fabrication process for very thin films, without crystalline defects on various substrates, is required. Single-crystalline VO2 thin films on (0001) plane of a sapphire substrate have been synthesized by a laser ablation method. The quality of VO2 was examined by X-ray diffraction and RBS/C method. The eleetrieal resistanee and the optical transmittance of the VO2 film were measured under inereasing and deereasing temperatures. At a temperature of 68 °C, an abrupt transition of resistanee from metal to... 

Since one common use of oxide films is for transparent, conducting coatings, the resistivities of these films were usually measured. Table 2.2 shows some basic electrical and optical properties of some of these films. 

Oxide films are often deposited becanse of their electrical (resistance) and optical properties. A selection of snch properties of CD oxides is given in Table 2.2. 

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