Showing papers on "Sputter deposition published in 1975"

Sputter coating with charged particle flux control

Abstract: Substrate heating during sputter coating, due to charged particles, is controlled by the use of an auxiliary magnet in the vicinity of the substrate. The magnet is arranged to either increase this charge particle flux, in situations in which additional heating is desired, or reducing this charge particle flux in situations in which heating is detrimental (e.g., the sputter coating of heat sensitive substrates such as polymer films).

Low‐voltage triode sputtering with a confined plasma. Part II: Plasma characteristics and energy transport

Abstract: The plasma characteristics of a triode low‐voltage sputtering (LVS) system have been measured. The current–voltage relationships in the confined plasma discharge, of the target and of the substrate table, have been investigated as a function of pressure for Ar and Xe, with and without an axial magnetic field. The power dissipation and steady‐state temperature at the target and substrate table were also measured as a function of operating conditions. From these measurements the plasma potential and target current densities could be deduced. The application of these results to sputter deposition is considered.

Method and apparatus for supplying background gas in a sputtering chamber

Abstract: In a sputtering chamber where there is at least one target of some material comprising at least two elements which are to be sputtered as a compound onto a substrate within the chamber, a target having a plurality of edges is framed by a metallic shield to confine the sputtering to a forward direction and the background gas needed for maintaining stoichiometry of the sputtered material is injected directly inside of the shield so that immediately upon entry into the chamber a substantial portion thereof flows over the target. A perforated manifold running the length of an edge of the target releases the background gas to the target along its length.

Effects of DC bias on the fabrication of amorphous GdCo RF sputtered films

Abstract: An investigation has been made on the effects of a dc bias field applied to Gd 1-x CO x thin films during rf sputter deposition. Such films may possess uniaxial magnetic anisotropy with easy axis perpendicular to the plane of the film and may be used in magnetic bubble devices. Uniformity in composition, thickness and magnetic properties has been achieved and film composition has been controlled to within one percent. However, significant variations of magnetic properties were observed from film to film.

Sputter-coating of glass sheets or other substrates

Abstract: A cathode for use in the sputter-coating of thin films of a selected coating material on glass sheets and other substrates, and means for cooling the same. The cathode is of rectangular construction including a top wall, a bottom wall and side and end walls defining a closed chamber therein. The cathode is internally cooled by circulating a cooling medium, such as oil, under a constant head pressure, through a closed system in which the cathode is interposed, and means for continuously withdrawing air and any other gases from the system such that as the oil circulates through the cathode chamber it will exert a pressure, less than atmospheric pressure, upon the walls of said cathode and thereby reduce the pressure differential across the cathode walls.

Sputter gas pressure and dc substrate bias effects on thick rf‐diode sputtered films of Ti oxycarbides

Abstract: Films 1–10 μ thick have been prepared by rf‐diode sputtering from targets of TiO0.5C0.5, TiO0.25C0.75, TiC, and TiN. These films were deposited on commercial, cobalt‐bound, cemented, complex‐carbide cutting‐tool inserts. The inserts were sputter etched immediately prior to sputter coating. This etch was found to be essential for obtaining good bonding. The sputtered films were prepared under various conditions of argon gas pressure ranging from 3 to 56 μ and substrate bias from 0 to −200 V dc. The sputtered materials exhibited similar microstructures under the same deposition conditions. In general, it was found that higher pressures and less negative biasing gave a ’’cauliflower’’ structure. Reducing the pressure and increasing the negative substrate bias produced more columnar films with less porosity but at a reduced deposition rate for constant power input. X‐ray diffraction analysis and Auger spectroscopic analysis of the TiO0.5C0.5 target and a sputter deposited film showed only a slight reduction i...

Superconducting properties of getter‐sputtered V3Al thin films as a function of sputtering gas, pressure, and substrate temperature

Abstract: Superconducting transition temperatures of V3Al thin films prepared by getter sputtering have been found to vary significantly not only with variation of the deposition temperature, as previously reported, but also with variation of the deposition pressure and composition of the sputtering atmosphere. The film composition measured at Tc maxima obtained by varying the deposition temperature for nonoptimum pressures was found to depart significantly from the 3 : 1 stoichiometry. High‐deposition pressures PD ≳175 mTorr are associated with films containing an excess of Al, while deposition pressures of less than 60 mTorr result in V‐rich films. With near‐optimum film deposition conditions for Ar, 155 mTorr pressure, and a deposition temperature of 800 °C, we have obtained a peak superconducting transition temperature of 11.8 °K.

High-rate sputtering of Nb-Al-Ge and Nb-Al superconductors

Abstract: High quality Nb-Al-Ge and Nb-Al superconductor deposits, up to 1 mm thick, were made at a rate of 1 μm/min using high-rate sputtering techniques. High-rate sputtering eliminates most of the fabrication problems generally encountered with these materials. Reasonable quantities of high-field superconductors can be made at acceptable cost for practical applications by high-rate sputtering. Highly reflective metallic mirror surfaces on these deposits indicate a high quality, even in thicknesses up to 1 mm. The deposits were completely free of voids and they did not seem to be overly brittle either before or after heat treatment. Crystal structures for deposits made at 20°C were not clearly defined, but probably were body-centered-cubic (bcc). Heat treatment between 550°C and 850°C completely transformed the bcc deposits to extremely small (350 A) grains of the A-15 crystal structure. The A-15 phase formed by heat treatment for 1 hr to 5 days at 750°C was metastable and supersaturated with Al and Ge. Deposition and heat conditions for decomposition of the metastable A-15 phase were identified. The highest critical temperatures (18°K) were observed only in those deposits containing undecomposed metastable A-15 phase. To assess practical use of the sputtered superconductors, 1- to 2-m lengths of ribbon and filamentary Nb-Al-Ge superconductor were produced on ribbon and wire substrates. It also was found that an excellent superconductor-stabilizer bond can be formed by high-rate sputter deposition of copper stabilizer onto heat-treated Nb-Al-Ge and Nb-Al superconductors.

Sputtering Yield on Ion Beam Sputtering Method

Abstract: The sputtering yield, especially as a function of ion incident angle, has been investigated experimentally and theoretically.The sputtering yields are obtained by measuring the decrease of material weight after ion bombardment. The experiments are carried out by sputtering silicon (111), silicon (100) and copper surfaces with 1 keV argon ions from Kaufman type ion source.Trajectories of incident ions which are scattered with target atoms are calculated by Monte Carlo simulation based on the LSS theory.The dependence of the ion incident angle on the sputtering yield can be explained as the competition between the effects of sputtering and backscattering.

Target and substrate interactions in bias sputter deposition

Abstract: During bias sputter deposition, the accumulation rate is found to vary significantly with impressed substrate bias. In the case of rf bias sputter deposition, the rate may increase or decrease depending on the biasing method. Measurements of the harmonic content of the radiation from a rf sputtering discharge have been made as a function of impressed substrate bias, both dc and rf, and for self bias obtained by tuning of the substrate circuit. These measurements indicate that for rf sputter deposition with dc bias, the target and substrates are non‐interacting. For rf self‐bias operation, the two circuits interact strongly, modifying the discharge characteristics to allow the dissipation of greater amounts of useful power.

Lamellar Composites Formed by Sputter Deposition; Properties and Potential Application to Turbine Blades

Abstract: : This report presents the results of the research done during the second year or Phase II of an investigation of the properties and behavior of lamellar composites formed by sputter deposition Two approaches have been investigated in parallel in Phases I and II of the contract Both were expected to result in yield strengths on the order of 1% or more of the modulus of the composite material The thin-layered approach, with about 50 A thick layers, was expected to derive its strengthening from interface effects between layers and the small thickness of the layers The compound-forming approach, with about 2000 A thick layers, was expected to derive its strengthening from the bulk properties of the components and their reaction products

Method of forming an overlayer including a blocking contact for cadmium selenide photoconductive imaging bodies

Abstract: A major surface of a cadmium selenide body is exposed within a reactive sputtering apparatus to controlled bombardment with electrons, and to controlled simultaneous reactive sputter deposition of an overlayer including aluminum and oxygen.

Ion Impact Chemistry in Thin Metal Films; Argon, Oxygen and Nitrogen Bombardment of Tantalum

Abstract: Nitrogen bombardment of tantalum thin films is shown to produce large variations in resistivity (p) and temperature coefficient of resistivity (TCR) with ion dose, and electron diffraction shows that these changes are probably due to the formation in the films of Ta2N and TaN. Films were prepared by evaporation in two quite different vacuum systems and by sputter deposition in an argon environment and the amount of oxygen in the as deposited tantalum films seems to play an important part in the magnitude of the variations of p and TCR.

Lead-Tin Telluride Sputtered Thin Films for Infrared Sensors

Abstract: : A study was carried out aimed at preparing thin ternary compound films suitable for infrared sensor application. An investigation was pursued to control or optimize the structural, compositional, electrical and electro- optical film properties by means of well defined deposition parameters and conditions. Techniques were first developed for sputtering single crystal thin films of lead tin telluride (PbSnTe) on barium fluoride and calcium fluoride substrates. Both supported discharge and ion beam sputtering were used. The sputtering gas was argon. Most data was obtained by supported discharge sputtering. Thirteen sputtering targets of PbSnTe were used with ratios of tin to total metal (lead plus tin) of x = 0.15 to x = 0.32. Some targets were prepared metal or tellurium rich but most were stoichiometric, i.e. having the same number of tellurium atoms as metal atoms. The upper substrate temperature for single crystal growth was about 350 C and the lower temperature ranged from about 225 to 300 C for growth rates from 0.5 to 2.5 micrometers hr. Outside this temperature-growth rate regime the films were not single crystal. The x-value of the deposited film, which defines the energy gap, was found to be controllable by the x-value of the target, the substrate temperature, and the deposition rate. Aside from film x-values, the stoichiometry of the film materials was found to be also controllable by adjustment of the substrate temperature and deposition rate. Complete stoichiometry, which is associated with the lowest achievable carrier concentrations, was found to occur at critical temperature- rate products - which differ with different target x-values.

Effect of system parameters on substrate bias during D.C. and R.F. sputter deposition

Abstract: When an electrically isolated substrate holder is immersed in a gas discharge, as in sputter deposition, the holder and substrates are exposed to a bombardment by energetic secondary electrons which may result in large substrate bias voltages. The induced substrate potential is effected by many system parameters. In this investigation, we have measured the variation of bias at an electrically floating substrate as a function of gas pressure and target to substrate separation for both a.c. and r.f. sputtering discharges. In the case of d.c. sputtering the voltages in question may attain negative potentials of up to 1 kv. Operating under these conditions will cause severe heating of the substrates and the growing deposits. H.F. sputtering discharges on the other hand, induce relatively small negative (<-100 V) and positive voltages at the substrate. These small positive biases have been shown to markedly affect the properties of r.f. sputtered metal films. In the case of r.f. sputter deposited chromium, electrically floating the substrates resulted in deposits which were only approx. 70% dense.

Cadmium stannate selective optical films for solar energy applications

Abstract: Efforts concentrated on reducing the electrical sheet resistance of sputtered cadmium stannate films, installing and testing equipment for spray coating experiments, and sputter deposition of thin cadmium sulfide layers onto cadmium stannate electrodes In addition, single crystal silicon wafers were coated with cadmium stannate Work also continued on the development of the backwall CdS solar cell

Thin Film SiO2 Deposition by RF Sputtering onto the Anodic Ta2O5 Film

Abstract: Here, deposition of SiO2 film by RF-sputtering onto the anodic Ta2O5 film for fabrication of an SiO2-Ta2O5 thin film capacitor is reported. Reproducible film deposition rate is achieved within the accuracy of 3% by decreasing the influence of adsorbed gases in the vacuum chamber. Argon pressure is adjusted in order to obtain the uniform deposition of the SiO2 film. The thickness distribution is less than 3% within the area covered by 70% of target radius. The standard deviation of capacitance due to the distribution of SiO2 films is about 2.5% of the average capacitance.The substate temperature should be precisely controlled during RF-sputtering for the realization of the capacitor with excellent electrical characteristics. The high substrate temperature causes deterioration of Ta2O5, but the SiO2 film deposited at low temperature has poor life stability and large capacitance change in moisture. The optimum substrate temperature is about 150 °C for the SiO2 film deposition onto the anodic Ta2O5 film.

Electrical Properties of Vacuum-Deposited Titanium Thin Films

Abstract: The electrical properties of vacuum-deposited titanium thin films on the glass substrate are studied experimentally in relation to some physical conditions of deposition.When the evaporation of titanium and deposition of the film on the substrate is held under the conditions in which the atmosphere has a pressure less than 5 × 10-8 Torr and the substrate is intentionally not heated, the resistivity of the films is converged into a constant value of nearly 90 μΩ-cm independent of the sort of atmosphere gases, which value is about twice as large as that of the bulk titanium metal.As the pressure of the gas introduced to the vacuum chamber during deposition is increased, the resistivity of the produced films also increases in the case of oxygen, nitrogen and air; however, it shows almost no increase in the case of argon until it's pressure reach 5 × 10-5 Torr.When the substrate temperature during deposition is increased, the resistivity of the produced film reveals indistinct minimum value in the gently sloping change at about 230°C temperature and it's temperature coefficient becomes maximum at the same temperature.A temperature characteristic of resistance of ultra-high vacuum deposited film at 400°C temperature substrate shows reversible variation by the heat-treatment in vacuum; however, that of the deposited film on the substrate which is not heated shows a small irreversible one. The poorer the vacuum during the deposition is, the more remarkable is the degree of irreversibility, and the irreversible change is interpreted by the crystallization of the films during heating.The relation between the resistivities of the above described films and their temperature coefficients shows a small deviation from the Matthiessen's law in a fine straight line. This deviation will be interpreted by the island or grain structure of the thin film and by the gas adsorption on the grain boundary.