Hollow Cathode Magnetron Sputtering Research Articles

High-rate deposition of ultra-thick silver film by hollow cathode magnetron sputtering

The deposition of high-performance micro-sized ultra-thick silver films is a critical issue. Hollow cathode magnetron sputtering is one of the promising techniques for depositing ultra-thick silver films. A novel cylindrical “three-dimensional magnetron sputtering” (3-DMS) magnet pack presented here was developed based on a conventional hollow cathode magnet pack to deposit high-performance ultra-thick silver film at a high rate. A stable process condition at the average power of 4 kW is realized by the new cylindrical “3-DMS” magnet pack's 137.5 mm diameter targets and a specially designed cooling well. Comparison of deposition rates with different power supplies and at different average power levels are discussed. The behavior of electrons on the target surface in this magnetic field arrangement is investigated using COMSOL Multiphysics software. The composition, topography, mechanical properties and residual stress of the ultra-thick silver film deposited by different sputtering modes (DCMS, HIPIMS, and Pulsed DCMS) are also discussed.

Comparison between conventional and hollow cathode magnetron sputtering systems on the growing of titanium dioxide thin films: a correlation between the gas discharge and film formation

This paper reports the deposition of titanium dioxide thin films on p -type Si(100) substrates using two techniques called conventional magnetron sputtering (CMS) and hollow cathode magnetron sputtering (HCMS). The influence of the plasma parameters on the film characteristics (topography, morphology and crystallinity) was investigated. Films were deposited at different oxygen concentrations (in the Ar + O 2 gas mixture) and axial distances for fixed values of working pressure (5.0 mTorr) and DC power (55 W). They were analyzed by profilometry, AFM and XRD. The gas discharge was diagnosed by single Langmuir probe and OES. Under experimental conditions used in this work, results show that HCMS favors the growing of rutile phase due to the increase of the energy on the film surface caused by the hollow cathode effect. On the other hand, films deposited by CMS present preferentially anatase phase due to the low energy transferred to the growing film. Further studies regarding the influence of plasma properties on the films formation were done in order to understand the plasma-surface correlation.

Effect of oxygen concentration and system geometry on the current–voltage relations during reactive sputter deposition of titanium dioxide thin films

Current–voltage relations at different magnetron sputtering systems and gas mixtures were studied during reactive sputter deposition of titanium dioxide thin films. The main goal of this work was to investigate the influence of reactive gas mixture (Ar + O 2) and system geometry on the electrical characteristics of the discharge. The geometries utilized were the conventional magnetron sputtering, hollow cathode magnetron sputtering and triode magnetron sputtering. A change in the system geometry leads to a change in the electric field distribution, which alters the working range of the discharge voltage and magnetron efficiency. It is noticed that the discharge voltage at constant current can be reduced when the geometry is altered from conventional magnetron to hollow cathode magnetron or triode magnetron, at the same time the magnetron efficiency is increased when hollow cathode magnetron or triode magnetron are used instead of conventional magnetron sputtering.

Numerical analysis of geometry effects for target re-deposition during low pressure hollow cathode magnetron sputtering

During low pressure ionized metal physical vapor deposition (PVD) of Cu seed layer for microprocessor interconnects, the re-deposited Cu film on the hollow cathode magnetron (HCM) target may fall off and damage the Cu film on the wafer. An analytical view factor model based on the analogy between metal sputtering and diffuse thermal radiation was used to obtain re-deposition profiles for HCM targets in low pressure (below 0.1 Pa) Cu ionized PVD. The model predictions indicate that there is an inherent non-uniformity in the re-deposition profile even for uniform sputtering over the entire HCM target. The predicted re-deposition profile agrees with experimental observations. Subsequent target redesign studies found that the non-uniformity in the re-deposition profile could be mitigated by using a conical sidewall between the top disk and the cylindrical sidewall or reducing the length of the cylindrical sidewall.

Titanium dioxide thin films deposition by direct current hollow cathode magnetron sputtering

Cylindrical hollow cathode magnetron sputtering (HCMS) system was used to deposit crystalline titanium dioxide thin films on p-Si (100) substrates. For a fixed pressure of 0.6 Pa total gas flow rate of 20 sccm and power of 55 W, the influence of the oxygen percentage in the Ar+O 2 gas mixture on the structural and surface properties of the films was studied by profilometry, XRD and AFM. The substrates were placed inside the hollow cathode at different positions along its symmetrical axis. Numerical simulations of cathode ion collection probability (CICP) were done in order to compare calculated data with the deposition process characteristics. The results indicate that the deposition rate and the surface roughness gradually decrease with the distance from the bottom of the cathode, due to the decrease of the CICP. The increase of the oxygen percentage in the gas discharge influences directly the deposition rate and decrease the surface roughness. The XRD analyses show that all the films are crystalline with predominant anatase (101) and rutile (110) orientations.

Influence of Electronegative Gas on the Efficiency of Conventional and Hollow Cathode Magnetron Sputtering Systems

The aim of this work is to study the influence of electronegative gas (oxygen at different concentrations) on the electrical characteristics of two configurations of magnetron sputtering systems, namely Hollow Cathode Magnetron Sputtering (HCMS) and Conventional Magnetron Sputtering (CMS). A comparison of the plasma impedances and magnetron efficiency of these systems were carried out through the current-voltage characteristics of the discharges operating at the same pressure and different oxygen concentration on O2/Ar mixtures. The results showed significant variations in the plasma impedance and magnetron efficiency, indicating that HCMS system presents better electrical characteristics than CMS system, i.e., low plasma impedance and high magnetron efficiency. The results indicate that HCMS system is a very interesting technique to be used as deposition system in micro and nanoelectronic processes.

Off-axis growth of AlN thin films by hollow cathode magnetron sputtering under various nitrogen concentrations

Amorphous and crystalline AlN thin films were deposited on Si (100) substrates by off-axis hollow cathode magnetron technique. The evolution of the crystalline orientation and the morphology of AlN thin films have been investigated depending on the nitrogen concentration. It has been demonstrated by using a combination of mass spectrometry, X-ray diffraction and atomic force microscopy techniques, that the film crystallinity and surface roughness are related with the nitrogen concentration. The results show that the monitoring of Al + and AlN + species by mass spectrometry proved to be an important new method to prescribe the plasma conditions for growing amorphous or crystalline films.

Duplex surface treatments on AL7075-T6 alloy against fretting fatigue behavior by application of titanium coating plus nitriding

The improvement of fretting fatigue resistance of AL-7075 is studied using surface treatments including nitriding and titanium coating by hollow cathode discharge (HCD) and magnetron sputtering techniques. The experimental results indicate that surface nitriding reduces the fretting fatigue resistance of the material. Titanium coating, using HCD technique, may increase the fatigue life up to 85% at low working stresses, while at higher stresses the increase is not considerable. Titanium coating, using magneto sputtering technique, may increase the fatigue life up to 77% at low working stresses, while at higher stresses it gives rise to the reduction in fretting fatigue life. Duplex treatment including nitriding with no temperature control, plus titanium coating by HCD technique, gives rise to the reduction in fatigue life. Duplex treatment including nitriding with substrate's temperature control plus titanium coating by DC magnetron sputtering technique increases the fatigue life up to 185% at low stresses and up to almost 60% at higher stresses.

Oxygen diffusion in YBa 2Cu 3O 7− δ films with different microstructures

We have investigated the oxygen out- and in-diffusion in epitaxial c-axis oriented YBa 2Cu 3O 7− δ films from isothermal four-point electric resistivity measurements. The films were grown by two different deposition methods: off-axis pulsed laser deposition (PLD) and hollow-cathode magnetron sputtering (HCMS). Chemical diffusion relaxation times have been determined for the out- and in-diffusion of oxygen at temperatures from 500 K up to 800 K. Both types of films yielded the same activation energy of about E A=1.1 eV for the diffusion processes. However, at the same temperature, differences in the diffusion relaxation times were observed. This difference results from the different morphologies and microstructures we have studied with scanning electron microscopy (SEM). Additionally, these results are compared to sputtered YBa 2Cu 3O 7− δ films passivated by amorphous Si–C–H–O–N overlay films. The activation energy in these films was about 1 eV, and the diffusion relaxation times were much larger than in the samples without the overlay.

Processing of continuously reinforced Ti-alloy metal matrix composites (MMC) by magnetron sputtering

The present work deals with a novel vapor synthesis route, the matrix-coated fiber process, for producing SiC fiber reinforced Ti–6Al–4V and Ti 3Al–Nb ‘orthorhombic’ titanium aluminide composites. In this process, the matrix alloys were directly deposited on SiC fibers by magnetron sputtering. The matrix deposition was conducted both as a batch process, wherein short-length fibers were coated with the matrix material using a planar magnetron sputtering system, as well as a continuous process, in which the matrix was deposited on continuous SiC fibers using a reel-to-reel hollow-cathode magnetron sputtering system. The matrix-coated fibers were consolidated to produce unidirectionally reinforced composite panels. Unreinforced matrix alloy samples were also fabricated using the same sputtering and consolidation conditions. Following heat treatments, the microstructural evolution in these materials were studied. Tensile tests at room temperature were also conducted on matrix and composite specimens. The results indicated that PVD foils and fiber coatings can be heat-treated to obtain microstructures similar to those obtained via conventional processing approaches. Further, the room-temperature tensile properties of PVD foils are comparable to conventionally rolled foils or sheets.

Thermoelectric and thermomagnetic effects in Nd 1.85Ce 0.15CuO x epitaxial thin films

Epitaxial, c-axis oriented Nd 1.85Ce 0.15CuO x thin films have been fabricated on (100) SrTiO 3 substrates by hollow cathode magnetron sputtering. The mixed state of the films has been characterized by measuring the longitudinal resistivity and Nernst effect in magnetic fields up to 6T applied parallel to the c-axis. From the resistivity data an upper critical field slope dH c2/ dT = −0.35 T/K was obtained for films with T c ≅ 22 K corresponding to an ab-plane coherence length ξ ab = 79 A ̊ . From the Nernst effect data the temperature derivative of the transport energy of magnetic flux lines was derived to dU φ / dT = −2.4 × 10 −13J/Km. At T = 18 K and H = 0.5 T the transport entropy of magnetic flux lines was obtained to S φ = 1.6 × 10 −14 J/Km. These values are in reasonable agreement with the prediction of time dependent Ginzburg-Landau theory. The measured data are compared to those obtained for epitaxial YBa 2Cu 3O 7−δ and Bi 2Sr 2CaCu 2O 8+ x thin films.

In-situ measurements of ion implantation effects on YBCO superconducting films

This superconducting films of YBa 2Cu 3O 7 have been deposited on SrTiO 3 substrates using a home-made hollow cathode magnetron sputtering system. The samples were placed on a variable-temperature target stage of a 200 keV implanter and then bombarded by O + to different doses. The electrical resistance of the samples and its dependence on both ion dose and temperature were measured in situ. Our experimental results reveal that the resistive behavior is extremely sensitive to ion dose, and the ion damage has a strong effect on the transport properties of these films.

Deposition, characterization, thermo-chemical compatibility and failure analysis of multi-layer coated silicon-carbide fiber-reinforced metal-matrix composites

Thin films of La 2O 3, ZrO 2, TiAlN, TiN, Al 2O 3 and Ti have been synthesized on SiC fibers using rf/dc hollow cathode magnetron sputtering source. These coatings have been designed and implemented as a combination of diffusion barrier and compliant layer for a NiAl intermetallic matrix. The structural, microstructural, surface morphological and compositional properties of these thin films have been investigated as a function of deposition parameters. Coated fibers embedded in NiAl matrix were subjected to high-temperature treatment and were studied for the damage and the interdiffusion of these ceramic layers. The thermo-chemical compatibility of, and the fabrication-process-induced physical damages to, ceramic coatings are discussed in this paper and alternate methods for the fabrication of fiber-reinforced composites are suggested.

Superconducting transport properties of YBa 2Cu 3O 7−δ films grown by hollow cathode magnetron sputtering

YBaCuO films were in situ grown using hollow cathode magnetron sputtering on substrates having different lattice constants. Transport properties show that the films grown on lattice matched substrates have higher critical current densities due to better grain alignment and the consequent reduction in the thickness of the grain boundaries.

Very high critical current densities in YBa/sub 2/Cu/sub 3/O/sub 7- delta //Nd/sub 1.83/Ce/sub 0.17/CuO/sub x/ superlattices

The critical current density of YBa/sub 2/Cu/sub 3/O/sub 7- delta //Nd/sub 1.83/Ce/sub 0.17/CuO/sub x/ (Y/Nd) superlattices grown heteroepitaxially by hollow cathode magnetron sputtering was measured in magnetic fields perpendicular and parallel to the c-axis. The thickness d/sub Y/ and d/sub Nd/ of the individual Y and Nd layers ranged between 50 and 400 AA. In superlattices with modulation periods below a critical wavelength Lambda /sub c/=450 AA the Y layers are coherently strained, whereas in those with modulation periods above Lambda /sub c/ the coherency strain starts to relax, resulting in the formation of a high density of misfit dislocations. Very high zero field critical current densities up to 1.1*10/sup 7/ A/cm/sup 2/ were observed for multilayers with a modulation period just above Lambda /sub c/. For B perpendicular to the c-axis, the critical current density J/sub c perpendicular to / is almost independent at B up to a certain field ( approximately=2 T for d/sub y/=100 AA) that corresponds to the lower critical field of the Y layers. J/sub c perpendicular to / values as high as 2*10/sup 6/ A/cm/sup 2/ were obtained for B=1 T and T=77 K. The angular dependence J/sub c/( phi ) is determined solely by the magnetic field component parallel to the c-axis demonstrating the two-dimensional nature of the superlattices.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

7468. Effect of deposition parameters on properties of films deposited on fibers by hollow cathode magnetron sputtering: M Ihsan and K Pourrezaei,J Vac Sci Technol, A8, 1990, 1304–1312

7468. Effect of deposition parameters on properties of films deposited on fibers by hollow cathode magnetron sputtering: M Ihsan and K Pourrezaei,J Vac Sci Technol, A8, 1990, 1304–1312

Cylindrical magnetron sputtering parameters for the growth of Y 1Ba 2Cu 3O 7−x thin films

We have studied cylindrical hollow cathode magnetron sputtering configuration with the aim of eliminating negative ion back-sputtering and realizing stoichiometric YBaCuO thin films from stoichiometric YBaCuO hollow cylindrical target. Results obtained indicate that under optimized sputtering conditions, YBaCuO films with excellent compositional uniformity within 1% of that of the target can be realized over an area almost 90% of the area covered by the inner diameter of the cylindrical target. Films deposited on unheated 〈100〉 MgO substrates and post annealed at 920°C in oxygen have shown a superconducting onset at 84 K and a zero resistance transition at 80 K.

Effect of deposition parameters on properties of films deposited on fibers by hollow cathode magnetron sputtering

Thin films of Al and TiN were deposited on SiC monofilaments using a hollow cathode magnetron sputtering system. The deposition rate was 1100 Å/min in the case of Al films deposited at 45.75 W direct current power and 5 mTorr sputtering pressure and 257 Å/min for TiN films deposited at 6 mTorr sputtering pressure, 6% N2, and 48 W applied direct current power. The effects of deposition parameters such as the direct current power, sputtering pressure, and substrate bias on the film microstructure were studied. The substrate temperature varied from 67.7 to 168 °C, which corresponds to a T/Tm value of 0.1 to 0.25. The Al films consisted of a voided columnar structure with domed tops. The width of the grains increased with increase in temperature over a T/Tm range of 0.1–0.22. When the pressure was increased, while keeping the power constant, the size of the columnar grains and voids decreased. The TiN films deposited at 6 mTorr exhibited zone 1 type structure with voids whereas for the films deposited at higher pressures, that is, 10 and 15 mTorr, the same effect of pressure as in the case of Al films was seen. When a bias is applied to the substrate, the voided structure is clearly suppressed. Preliminary studies show that bias sputtered films show better diffusion barrier properties against both Si and Al, after being annealed at 650 °C for 6 h, as compared to the films deposited without bias.

Summary Abstract: Aluminum deposition on optical fibers by a hollow cathode magnetron sputtering system

Summary Abstract: Aluminum deposition on optical fibers by a hollow cathode magnetron sputtering system

Hollow Cathode Magnetron Sputtering of Metallurgical Coatings

Hollow Cathode Magnetron Sputtering of Metallurgical Coatings