Sputtered oxide films

Many studies (50—56) have attempted to explain bulk conduction through anodic oxide films on tantalum foils or sputtered tantalum substrates. 

In XPS, chemical information is comparatively slowly acquired in a stepwise fashion along with the depth, with alternate cycles of sputtering and analysis. Examples of profiles through oxide films on pure iron and on Fe-12Cr-lMo alloy are shown in Fig. 2.9, in which the respective contributions from the metallic and oxide components of the iron and chromium spectra have been quantified [2.10]. In these examples the oxide films were only -5 nm thick on iron and -3 nm thick on the alloy. 

Sputtering i s presently the maj or thin-film process for the production of deicing coatings. The coating is satisfactory from an optical standpoint although transmission could still be improved, but it has poor scratch resistance and must be sandwiched between the two layers of safety glass. The CVD oxides films shown in Table 16.1 are particularly attractive since they are inherently abrasion resistant and could be used on the outer surface of the glass. 

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. 

Zhu Y, Uchida H, Yajima T, Watanabe M. 2001. Attenuated total reflection-Fourier transform infrared study of methanol oxidation on sputtered Pt film electrode. Langmuir 17 146-154. 

The most reliable and easy to control method of oxide films application is provided by either sputtering of an oxide layer (e. g., by a laser beiun), or evaporation of a thin metal zinc film (its resistance is usually 5-10 Ohm) from tantalum vessel onto a thoroughly prepared clean quartz substrate in a vacuum of Torr (containing no oil and... 

Ion Beam Deposition The most commonly used vacuum method for the rapid deposition of films (thin or thick) is sputtering (2M. This can be combined with ion beam techniques in a variety of ways (25) including (Figure 18) ion beam sputter deposition (IBSD) eg of oxide films or of hard carbon (26). In reactive systems the reactive gas is added to the argon ion beam. The properties of the deposited materials are modified substantially by varying the gas composition (Figure 19). 

In the case of oxide films it appears that the oxide is formed on the target (27, 28) and is subsequently sputtered onto the substrate. The oxide films formed (TiO, Ta O, SiO etc) are amorphous and have high refractive indices andDlow porosity which are indicative of high density. 

K.G. Kreider, M.J. Tarlov, and J.P. Cline, Sputtered thin-film pH electrodes of platinum, palladium, ruthenium, and iridium oxides. Sens. Actuators B. 28, 167-172 (1995). 

K.R. Zhang, F.R. Zhu, C.H.A. Huan, A.T.S. Wee, and T. Osipowicz, Indium-doped zinc oxide films prepared by simultaneous rf and dc magnetron sputtering, Surf. Interface Anal., 28 271-274, 1999. 

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. 

L.J. Meng and M.P. dos Santos, Properties of indium tin oxide films prepared by rf reactive magnetron sputtering at different substrate temperature, Thin Solid Films, 322 56-62, 1998. 

Polysilicon (used as a sensor heater) was delineated by etching in a SFg plasma. A 1 pm layer of CVD Si02 was deposited, and a 100 nm tin oxide film was subsequently sputter-deposited (Figure 1b). 

The rapid development of solid state physics and technology during the last fifteen years has resulted in intensive studies of the application of plasma to thin film preparation and crystal growth The subjects included the use of the well known sputtering technique, chemical vapour deposition ( CVD ) of the solid in the plasma, as well as the direct oxidation and nitridation of solid surfaces by the plasma. The latter process, called plasma anodization 10, has found application in the preparation of thin oxide films of metals and semiconductors. One interesting use of this technique is the fabrication of complementary MOS devices11. Thin films of oxides, nitrides and organic polymers can also be prepared by plasma CVD. 

The intensities of the integrated signals may be evaluated on the basis of well-characterized standards. Consequently ISS provides qualitative and quantitative information on the composition of the surface. Noble gas ions that penetrate the first layers of the surface are backscattered as neutrals, and thus may not pass the energy analyzer. As a consequence, only ions backscattered at the first atomic layer are detected and the method is sampling the outmost atomic layer. A soft sputter process by noble gas ions yields an ISS depth profile with atomic depth resolution. Therefore ISS has been applied to the study of very thin oxide films, as e.g. of passivated Fe/Cr alloys. This method may be applied in addition to XPS due to its high depth resolution. 

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