Sputtering Deposition Parameters Research Articles

Sputter deposition of a corrosion-resistant amorphous metallic coating

Starting with corrosion-resistant amorphous Fe32Ni36Cr14P12B6 alloy material, rf sputter deposition has been successfully used to deposit amorphous thin films very similar in composition onto low-carbon (i.e., 1008) steel. The effects that varying sputter deposition parameters has on a film's corrosion resistance, microstructure, and chemical composition have been examined. Optical, scanning, and transmission electron microscopy, Auger depth profiling, and x-ray diffraction were used to characterize the microstructure and composition of the films, while the corrosion resistance was determined by anodic polarization in basic and acidic solutions. A ∼4000 Å thick amorphous film sputtered at ambient temperature onto a 0.05 μm polished 1008 steel substrate improved the corrosion resistance of the steel in a buffered borate solution by lowering the steel's critical current density by two orders of magnitude and by raising its corrosion potential by ∼0.4 V. Bias voltage sputtering was required to produce a film with properties that could withstand a sulfuric acid solution. For example, a film sputtered at – 70 V at ambient temperature onto a steel substrate passivated in sulfuric acid solution, whereas the steel was completely active in this solution without the sputtered film. Passive current densities in this case were ∼2x102μA/cm2. In both solutions the improved corrosion resistance was exhibited by films with lower oxygen content and a denser microstructure. Thus a direct correlation between corrosion resistance, microstructure, and composition is shown.

Effects of substrate bias on the resistivity and microstructure of molybdenum and molybdenum silicide films

A continuous series of Mo-Si alloys (Mo x Si 1− x ), with 0.3 ⩽ x ⩽ 1, have been deposited by reactive magnetron sputtering of molybdenum in silane and argon plasma. The effects of sputter deposition parameters such as the deposition rate, substrate temperature, substrate bias and gas flow conditions on the resistivity of molybdenum and molybdenum silicide films are reported. The resistivity of molybdenum films shows a pronounced decrease with an increase in the negative substrate bias and the rate of film growth. An electrical resistivity as low as 7.8 μΩ cm has been obtained in molybdenum films by optimizing the deposition conditions. The resistivity of MoSi 2 films, measured after annealing them at 1000°C for 1 h in nitrogen ambient, shows a broad minimum at −75 V bias. However, the effect of bias is not as pronounced as for molybdenum. The changes in the resistivity of molybdenum and MoSi 2 films are attributed to the degree of oxygen contamination and microstructural modifications during growth.

Study of r.f. magnetron-sputtered MoSe2 films by electron spectroscopy for chemical analysis

Abstract Thin MoSe2 films were prepared by r.f. planar magnetron sputtering and studied by photoelectron spectroscopy. The chemical state of the surface species was identified by the location and separation of the 3d lines of molybdenum and selenium. The chemical shifts of these lines for the thin films were found to be in good agreement with those of a stoichiometric single-crystal reference. Quantitative analysis was conducted by determination of peak area and peak height sensitivity factors. The results show the influence of the sputter deposition parameters on the surface chemical composition of the films.

Structure and properties of sputter-deposited CdTe

CdTe films were sputter deposited in thicknesses of 2 to 10 μm using systematically selected deposition conditions. Crystal structure was controllably varied from sharp hexagonal (wurtzite), to highly faulted, to sharp cubic (sphalerite). Electrical resistivity was controllably varied from 10 4 to 108 Ω.cm for p-type material and from 106 to 108 Ω.cm for n-type films. Infrared transmission characteristics for wavelengths near the band edge were controllably varied from highly transparent to highly absorptive. The variation in both the structure and properties of the deposited films was shown to result from the influence of sputter deposition parameters on film composition (stoichiometry). Deposition parameters which influence grain size in the polycrystalline films were established, and grain sizes ranging from 0.2 to 3 μm were produced. Control of the electrical properties of the films by doping with several different acceptor impurities was only slightly successful.

Preferred Orientation in RF–Sputtered ZnO Films

The influence of substrate material and sputter deposition parameters on the degree of preferred perpendicular orientation of ZnO films is studies and compared to earlier results on ZnO films having a preferred parallel orientation. Films sputtered onto a very thin (200 Å) film of SiO2 on top of the counterelectrode have the largest degree of preferred orientation. A relatively high sputter rate of the order of 400 Å/min which results in a strong substrate heating has a beneficial effect on both preferred orientations. A negative substrate bias voltage leads to an increase in the degree of preferred orientation whereas it results in a loss of orientation in perpendicular oriented ZnO films. There exists a good correlation between the degree of preferred orientation as determined by X-ray diffractometry and electromechanical coupling coefficient as determined by ultrasonic pulse echo measurements.