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Metal films were deposited by the partially ionized beam technique, using a source with high ionization efficiency. Some characteristics of the source were investigated. Metals with low, medium and high melting temperatures were used for deposition. It was found that ionization efficiency of low-melting metals is higher than that of metals with medium and high-melting temperatures. The effect of the...
In this work we discuss in-situ cleaning of Si (100) and Si (111) using a hydrogen atom source, with particular reference to carbon and oxygen removal and the quality of the substrate surface after treatment. It is shown that hydrogen atoms are effective at surface carbon removal at temperatures around 350°C and may contribute to lowering the thermal desorption temperature of thin oxides. Exposure...
Tin doped indium oxide (ITO) films were deposited on glass substrates by rf reactive magnetron sputtering using a metallic alloy target (In-Sn, 90-10). The post-deposition annealing has been done for ITO films in air and the effect of annealing temperature on the electrical, optical and structural properties of ITO films was studied. It has been found that the increase of the annealing temperature...
The manner in which the coercivity, permeability and resistivity of films of Fe M X (M: Ta, Hf, Zr, Nb; X: N, C, Ar;) and Permalloy varied because of particular conditions during DC magnetron sputter deposition has been determined. The effects of reactive gases and substrate bias during the sputtering process were studied and the measured values for H c , μ and ρ were compared with the results...
Nitrogen molecular dissociation is studied in DC diode and thermionic triode glow discharges of pure nitrogen and nitrogen-argon mixtures. Optical emission spectroscopy is used to determine the relative proportions of atomic and molecular nitrogen in the cathode sheath and plasma regions of these discharges operated at -2 kV cathode bias in the range 0.1-10 Pa. The results show that for nitrogen-argon...
Most superconducting r.f. cavities are made of Nb. Their performance is closely related to the purity of Nb's surface. Adequate characterization tools are needed to qualify the cavity surface. An improvement of the classical ERD method of hydrogen analysis has been achieved using an electromagnetic (EXB) filter. Thus, the depth resolution in Nb was 17 nm. This method was used to select the best procedure...
A new approach and successful method of studying the turbomolecular vacuum pump. Gaede's equations and Becker's treatment lead to two equations k = f 1 (u 0 , s, g) and S = f 2 (u 0 , s, g), which connect the compression ratio k and the pumping speed S with the rotational speed u 0 , the tangent s of the blade's angle and the geometry g of such a pump. The design...
Determination of the concentration of hydrogen in zeolitic materials by Elastic Recoil Detection Analysis (ERDA) has been carried out. Irradiation effects of 2.5 Mev He 4 e + ions on the surface of hydrogenated silicon and zeolitic materials, e.g. Y-faujasite, NaH ZSM-5, SK-500 and an Algerian montmorillonite have also been investigated. Quantitative measurements allowed the determination...
An AFM and SEM study of the topography induced by 20 keV Si + , Ar + and Xe + ion bombardment of Si at 45° incidence angles and for ion fluences between 10 17 and 10 20 cm -2 has been undertaken at room temperature. All species generate an atomic scale random roughness, the magnitude of which does not increase extensively with ion fluence,...
Control of the density, composition, ionisation rate and arrival energy of species is one of the main objectives of research in the development of reactive magnetron sputtering. The deposition of the latest generation of multilayer and multi-component coatings requires the independent control of deposited flux parameters using fast response and reliable control systems. A review of recent advances...
A high temperature quartz crystal microbalance (HTQCM) was developed in order to extend its application range up to the Curie point (573°C) of the quartz resonators. It is shown that well matched quartz crystal resonators and even better, a dual resonator working in a differential measuring system, can minimize the temperature effect on the measuring signal, allowing mass measurements with an accuracy...
Different microstructural parameters like particle size, rms strain and dislocation density of thermally evaporated Cd 1-x Zn x Te (0 < x < 1) films of different thicknesses deposited on glass at different substrate temperatures have been studied. Optical band gap, absorption constant and refractive index of these films have been studied as a function of incident photon...
A review of the current status of ion assisted deposition of optical thin films is presented. The different kinds of ion sources and their relative merits and demerits are discussed. This is followed by a discussion of the various theoretical models currently in use to explain ion-surface interactions in such a process and finally the properties of oxide thin films deposited using ion assisted deposition...
Preliminary results are presented from a study of transition metal/InP reactions using mass and energy dispersive recoil spectrometry. 50 nm films of Ni, Pd and Pt were evaporated on InP substrates, heat treated in vacuum and subsequently analysed with X-ray diffraction and mass and energy dispersive recoil spectrometry using 77 MeV 127 I 10+ ions as projectiles...
The effect of a pre-filter on the sensitivity of a high-resolution quadrupole mass spectrometer (QMS) has been experimentally studied. The high-resolution QMS uses the condition of a higher stable zone in the Mathieu stability diagram where the higher zone is defined as zone II having a center of a = 2.83 and q = 3.02 in the a-q plane. The pre-filter of a short auxiliary quadrupole was added in front...
A method allowing one to obtain the analytic expressions for the calculation of the pressure distribution in complex vacuum systems consisting of a series of cylindrical and tapered tubes from different vacuum materials, for example, high vacuum systems of particle detectors for an accelerating complex, with consideration of the thermal and stimulated outgassing, is presented. A method of estimating...
A new heavy ion isochronous cyclotron U-400M has been built at Flerov Laboratory of Nuclear Reactions. Its vacuum chamber volume is 35 m 3 and its internal surface area is 375 m 2 . The total gas flow is approximately 1 l Pa s -1 . The pumping out is performed by six diffusion oil pumps having liquid-nitrogen-cooled traps. The total pumping-out speed of the pumps is 24,000...
Precisely known gas flows are required in various applications, as, for example, in generation of uhv calibration pressures, testing of vacuum pumps, and quantification of leak rates. Commercial thermoelectrical flow meters are convenient instruments, but neither fundamental nor available for small throughputs. Laboratory flow meters based on the volumetric method at constant pressure are well proven...
Thin film alloys of Al/Pt were produced by sputtering a binary target, comprising a piece of Al mounted adjacent to a piece of Pt, using a broad-beam Kaufman ion source. By suitable geometrical positioning of the target with respect to the substrate, different compositions of Al/Pt thin films were produced. The effect of irradiation by an additional 200 eV Ar ion beam during film deposition on the...
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