Influence Of Sputtering Conditions Research Articles

INFLUENCE OF THE RATIO OF GASE CONSUMPTION N<sub>2</sub>/Ar AND MAGNETRON POWER ON THE DENSITY AND STOICHIOMETRIC COMPOSITION OF TIN<sub>X</sub> FILMS SYNTHESIZED BY MAGNETRON SPUTTERING METHOD

The films of titanium nitride were deposited by direct current magnetron sputtering on the surface of singlecrystalline silicon samples in an Ar-N2 atmosphere for use as a diffusion barrier. The thickness and density of films were measured by X-ray reflectometry. The design of the MAGNA TM-200-01 installation has been changed to increase the supply of nitrogen into the chamber. The influences of sputtering conditions, including the flow rate of nitrogen and argon gases and their N2 /Ar ratios in the range of 1–60 in the chamber, magnetron power of 690–1400 W on the formation of TiNx films, their density and stoichiometric composition, were studied. It is shown that the value of x is affected not only by the N2 /Ar gas flow rate ratio, but also by the magnetron power. At the sputtering parameters 1200 W, N2 /Ar = 30, 0.8 Pa, 320 s and 100°C, a maximum density of 5.247 g/cm3 of a film was achieved, which corresponds to the composition TiN0.786 = Ti56N44. The presence of nanocrystalline film of titanium nitride and the absence of a nanocrystalline titanium phase were confirmed by photographic X-ray diffraction. It was found that for the synthesis of titanium nitride as close as possible to the stoichiometric composition TiN0.770 - TiN0.786, it is necessary to use magnetron power in the range of 900–1200 W, nitrogen rate of 30 cm3 /min with low argon flows of 1–5 cm3 /min.

Li Metal Anode with a LiZn Alloy Interlayer for Li-Metal Polymer Batteries

All-solid-state batteries (ASSB) require stable and safe Li metal anode, which needs surface preparation to increase lithium diffusion and impede the formation of dendrites. In this work, the formation of a thin LiZn layer on lithium metal using sputter deposition is reported. This method was selected due to the absence of solvents and by-products generated during the modification, for its rapidity and because the formation of the alloy is performed in a clean and controlled atmosphere. Zinc has been chosen for its low cost and high Li+ ion diffusion coefficient of the corresponding LiZn alloy that is 1000 times higher than lithium. Different parameters for the Zn deposition were investigated such as the distance between the Zn target and Li foil, the effect of substrate tilt and the direct current applied to the target. Electrochemical performance of LiFePO4/solid polymer electrolyte/Li ASSB demonstrated the superiority of the LiZn anodes and the clear influence of deposition parameters on the durability and performance at high C-rates. Scanning electron microscopy images of the cross-sectional view of LFP/SPE/Li stackings extracted from pouch cells after cycling showed an evident migration of Zn into the bulk Li metal anode as well as the formation of AlZn nanoparticles. In addition, the formation of Li dendrites was effectively reduced for the cells made with the LiZn-protected Li metal anode. Finally, we reported an interesting observation concerning the influence of sputter conditions on the variation of morphology of Li grains.

Nano-Scratch Response of Diamond-Like Carbon Film Deposited by Pulsed Direct Current Magnetron Sputtering

Diamond-like carbon (DLC) films are known for thermal, chemical and mechanical properties. Hydrogen free and hydrogenated DLC films are deposited using pulsed direct current magnetron sputtering. The influence of sputtering conditions on the nano-scratch properties of these films is investigated. Raman spectra reveals that structural disorder in the a-C:H matrix decreases with increase in acetylene flow. Increased acetylene flow reduces frictions, residual stress and retains hardness. The friction responses of the deposited defects free ultra-smooth films are influenced by pull off forces at low load and by formation of carbonaceous layer at high load.

Influence of sputtering conditions on the properties of aluminum-doped zinc oxide thin film fabricated using a facing target sputtering system

In this study, aluminum-doped zinc oxide thin films are deposited on a glass substrate using a facing target sputtering system, as a function of film thickness and input power, to study their crystallographic, optical, and electrical properties at various sputtering conditions. X-ray crystallography results revealed a (002) peak at approximately 34° with the highest intensity. The 200 nm film deposited at 100 W exhibited high crystallinity, the highest transmittance (92%), and lowest resistivity (1.4 × 10−3 Ω cm).

The influence of sputter conditions on the properties of LiPON and its interfaces

The solid-state electrolyte LiPON is synthesized using reactive magnetron sputtering. The correlation between plasma conditions and chemical composition of the layers is studied by X-ray photo electron spectroscopy, accompanied by electrochemical measurements of the ionic conductivity of the films. It is found that the plasma conditions in the vicinity of the substrate affect the lithium and nitrogen contents in a reciprocal manner. The target sputter-age and an additional bias potential to the substrate are identified as important parameters to optimize the performance of the layers. Based on this information, bilayer samples are prepared, consisting of LiPON and a cathode of LiFePO4. Chronopotentiometry at these bilayers reveals the importance of a low interface resistance, and moreover, it identifies an insufficient lithium content at the LiPON/LiFePO4 interface as a reason for high interface resistance. Nitrogen is also essential to increase the conductivity and hence, a lack of nitrogen at the interface is suggested to have the same consequence. It is shown how the interface resistance can be controlled by the preparation conditions to achieve an optimized performance.

Studies on the Structure and Properties of ZnSb Thin Films Deposited under Various Sputtering Conditions

In this paper ZnSb thin films were prepared by radio frequency magnetron sputteringfrom a stoichiometric Zn4Sb3 target followed by thermal annealing. The influence of sputteringconditions on microstructure, surface morphology, crystallinity and electrical transport propertieswere investigated. For the range of sputtering power of 50 W to 125 W and working pressure of 0.7Pa, it was found that the content of compound ZnSb phase in the films as well as film crystallinitycould be enhanced greatly by increasing the sputtering power, and this effect may be reinforced bydecreasing the working pressure to 0.2 Pa. At 0.7 Pa, A maximum value of 2.99 μW/cmK2 of powerfactor measured at room temperature was obtained at 100 W. The sample prepared at the samepower and lower pressure of 0.2 Pa has a room temperature power factor of 5.46 μW/cmK2 which isalmost doubled.

Influence of sputtering conditions on room-temperature fabricated InGaZnO-based Schottky diodes

Indium gallium zinc oxide (InGaZnO or IGZO) has attracted much attention in recent years for flexible and transparent electronics, because of its superior electric properties, optical transparency and low processing temperature. In this work, Schottky diodes with a structure of Pd/IGZO(100nm)/Ti/Au were fabricated by radio-frequency magnetron sputtering at room temperature without any thermal treatment. The relationship between different IGZO deposition parameters and the forward and reverse current-voltage characteristics of the diodes was systematically studied. We have experimentally revealed that an increase in the oxygen partial pressure during the sputtering process can effectively improve the barrier height of these diodes. However, either high oxygen partial pressure or high sputtering power leads to a deterioration of ideality factor and a decreased rectification ratio. By using relatively low sputtering power (≤70W) and low oxygen content of sputtering atmosphere (~2.5%), high-performance diodes have been achieved with high rectification ratio, low ideality factor, and high barrier height of 1.3×105, 1.14, and 0.73eV, respectively. All diodes with IGZO layer sputtered in oxygen-argon atmosphere show a high reversed breakdown voltage ~−6V.

Submicrometer Hollow Bioglass Cones Deposited by Radio Frequency Magnetron Sputtering: Formation Mechanism, Properties, and Prospective Biomedical Applications.

This work reports on the unprecedented magnetron sputtering deposition of submicrometric hollow cones of bioactive glass at low temperature in the absence of any template or catalyst. The influence of sputtering conditions on the formation and development of bioglass cones was studied. It was shown that larger populations of well-developed cones could be achieved by increasing the argon sputtering pressure. A mechanism describing the growth of bioglass hollow cones is presented, offering the links for process control and reproducibility of the cone features. The composition, structure, and morphology of the as-synthesized hollow cones were investigated by energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), grazing incidence geometry X-ray diffraction (GIXRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM)-selected area electron diffraction (SAED). The in vitro biological performance, assessed by degradation tests (ISO 10993-14) and cytocompatibility assays (ISO 10993-5) in endothelial cell cultures, was excellent. This allied with resorbability and the unique morphological features make the submicrometer hollow cones interesting candidate material devices for focal transitory permeabilization of the blood-brain barrier in the treatment of carcinoma and neurodegenerative disorders.

Magnetic Nanoparticles in “Amorphous Ferromagnetic Metal-Insulator” Nanogranular thin Films

A lot of factors limit possible applications of magnetic nanoparticles in medicine for drug delivery and magnetic hyperthermia therefore it is of primary importance to understand influence of classical and quantum-size effects, surface layers, interparticle distance, shape of nanoparticles on their magnetic properties. Magnetic nanogranular thin films, known also as nanocomposites, can be considered as a convenient model for such investigations as it is possible to tune easily many of mentioned above parameters by varying of the fabrication conditions. The ion-beam sputtering technique has been developed to prepare “amorphous ferromagnetic metal-insulator” nanocomposites with different concentration and parameters simultaneously in one technological cycle. This feature is achieved by using of a composite target (consisting of a metal and dielectric parts) with an asymmetric arrangement of the dielectric parts on the metal base. Influence of sputtering conditions and post-fabrication treatment on structural, magnetic, electrical and magnetotransport properties of magnetic nanocomposites in a wide range of metal volume fraction and distance between magnetic nanoparticles is being discussed.

Bi4V2O11 and BITAVOX.20 coatings deposited by reactive magnetron sputtering

Bi4V2O11 and BITAVOX.20 films were deposited by magnetron sputtering in reactive conditions from Bi, V and Ta metallic targets. The influence of sputtering conditions on the films composition was studied and then a structural study at variable temperature was carried out. Before annealing, the films were amorphous and the γ-Bi4V2O11 structure was obtained for a treatment at temperatures over 550 °C whereas BITAVOX.20 started to crystallise at 425 °C. In both cases, crystallisation occurred via an intermediate fluorite phase presenting a tetragonal deformation as already observed for other compounds with the Aurivillius structure.

Stabilization of sputtered gold and silver nanoparticles in PEG colloid solutions

In this study, a simple technique for preparation of colloid solution of metal nanoparticles in polyethylene glycol (PEG)/H2O is described. By this technique, stable colloidal metal solutions can be prepared ready for use without application of chemical reactions, stabilizers, or reducing agents. The nanoparticles are created by direct sputtering of metal into PEG. The influence of sputter conditions and the concentration of PEG/H2O on the properties of nanoparticles was studied. The nanoparticles were characterized by transmission electron microscopy, atomic absorption spectrometry, dynamic light scattering, and UV–Vis spectroscopy. UV–Vis spectra of gold nanoparticle solution exhibit localized surface plasmon resonance characteristic peaks located in the region 513–560 nm (PEG/H2O—1/1), 509–535 nm (PEG/H2O—1/9), and for silver nanoparticles in the region from 401 to 421 nm. Silver nanoparticles have a broader size distribution compared with gold ones. An appropriate choice of concentration, mixing, and deposition conditions allows preparing the stable solution of gold or silver nanoparticles.

Influence of sputtering conditions on the optical and electrical properties of laser-annealed and wet-etched room temperature sputtered ZnO:Al thin films

We explore the influence of the sputtering deposition conditions on the outcome of an excimer laser anneal and chemical etching process with the goal of producing highly textured substrates for thin film silicon solar cells. Aluminum-doped zinc oxide (ZnO:Al) thin films were prepared on glass substrates by radio frequency magnetron sputtering from a ceramic target at room temperature. The effects of the process pressure (0.11–1.2Pa) and oxygen flow (0–2sccm) on the optical and electrical properties of ZnO:Al thin films have been studied both before and after an excimer laser annealing treatment followed by a dilute HCl chemical etch. The as-deposited films varied from completely opaque to yellowish. Thin film laser annealing dramatically improves the optical properties of the most opaque thin films. After laser annealing at the optimum fluence, the average transmittance in the visible wavelength range was around 80% for most films, and reasonable electrical performance was obtained for the films deposited at lower pressures and without oxygen flux (7Ω/□ for films of 1μm). After etching, all films displayed a dramatic improvement in haze, but only the low pressure, low oxygen films retained acceptable electrical properties (<11Ω/□).

C-axis orientation and piezoelectric coefficients of AlN thin films sputter-deposited on titanium bottom electrodes

Aluminum nitride (AlN) reactively sputter deposited from an aluminum target is an interesting compound material due to its CMOS compatible fabrication process and its piezoelectric properties. To obtain high piezoelectric coefficients it is a necessary pre-request to synthesize films with c-axis orientation. Besides the influence of sputter conditions on the microstructure of AlN thin films the condition of the substrate surface is another important factor of utmost importance. In this study, the influence of 350nm thick titanium metallization DC sputter-deposited on SiO2/Si substrates at varying back pressure levels bp,Ti in the range of 2×10−3 to 14×10−3mbar on the c-axis orientation and the piezoelectric coefficients of 600nm thick AlN thin films is investigated. Besides the plasma power for Ti deposition (Pp,Ti=100W) the parameters for AlN synthetization are fixed to Pp=1000W and bp,AlN=4×10−3mbar in 100% N2 atmosphere. Basically, the surface roughness of the Ti bottom layer is the dominating factor resulting either in a high degree of c-axis orientation (i.e. at low bp,Ti values) or in an amorphous AlN microstructure (i.e. at high bp,Ti values). Under low pressure conditions, a smooth and dense surface characteristics is achieved due to a higher kinetic energy associated with the adatoms what is especially important at nominally unheated substrate conditions. The piezoelectric coefficient d33 decreases from 2.55 to 1.7pm−1 when increasing the titanium sputter pressure from 2×10−3 to 14×10−3mbar. When decreasing the Ti film thickness to 60nm and hence, reducing the root mean square roughness by a factor of about 2, the intensity associated with the AlN (002) peak is increased by a factor of about 1.7 demonstrating the direct impact. Furthermore, the highest values for d33 and d31 (i.e. 3.15pmV−1 and −1.28pmV−1) are determined.

Highly adherent bioactive glass thin films synthetized by magnetron sputtering at low temperature

Thin (380-510 nm) films of a low silica content bioglass with MgO, B(2)O(3), and CaF(2) as additives were deposited at low-temperature (150°C) by radio-frequency magnetron sputtering onto titanium substrates. The influence of sputtering conditions on morphology, structure, composition, bonding strength and in vitro bioactivity of sputtered bioglass films was investigated. Excellent pull-out adherence (~73 MPa) was obtained when using a 0.3 Pa argon sputtering pressure (BG-a). The adherence declined (~46 MPa) upon increasing the working pressure to 0.4 Pa (BG-b) or when using a reactive gas mixture (~50 MPa). The SBF tests clearly demonstrated strong biomineralization features for all bioglass sputtered films. The biomineralization rate increased from BG-a to BG-b, and yet more for BG-c. A well-crystallized calcium hydrogen phosphate-like phase was observed after 3 and 15 days of immersion in SBF in all bioglass layers, which transformed monotonously into hydroxyapatite under prolonged SBF immersion. Alkali and alkali-earth salts (NaCl, KCl and CaCO(3)) were also found at the surface of samples soaked in SBF for 30 days. The study indicated that features such as composition, structure, adherence and bioactivity of bioglass films can be tailored simply by altering the magnetron sputtering working conditions, proving that this less explored technique is a promising alternative for preparing implant-type coatings.

Effect of aluminum and indium co-doping on zinc oxide films prepared by dc magnetron sputtering

Aluminum and indium co-doped zinc oxide (AIZO) thin films were prepared by direct current (dc) magnetron sputtering on glass substrate in pure argon atmosphere. Three inches of zinc oxide ceramic with 0.5 wt.% of aluminum and indium doping was used as a target in static mode. The influence of sputtering conditions i.e. substrate–target distance, pressure and power on AIZO films was studied. The electrical resistivity and microstructure of thin films were investigated by the four point probe technique and the scanning electron microscope, respectively. The optical transmittance of AIZO films was measured by UV visible spectrophotometer in the wavelength of 300–1100 nm. Depending on the deposited conditions, highly transparent films up to 80% with low resistivities in the range of 2.6–7.9 × 10 − 4 Ω cm were achieved at room temperature. Possible mechanism in the processing which, ultimately, determines the physical properties of AIZO films will be discussed.

Influence of sputtering conditions on crystalline quality of AlN layers deposited by RF reactive sputtering

AbstractAluminum nitride (AlN) is increasingly demanded for use in semiconductor‐related industries. This study was undertaken for fabrication of high‐quality AlN thick layers using radio‐frequency (RF) reactive sputtering with a pure Al target. The AlN layers were sputtered homoepitaxially on high‐quality thin AlN layers on sapphire substrates for 1.5 h with 300 to 650 W at 573 and 773 K. The AlN thin layers were grown using sapphire nitridation before sputtering. A N2‐Ar gas mixture was used as the sputtering atmosphere and N2 gas flow ratio was changed from 20 to 60 vol%N2. In all sputtering conditions c‐axis oriented AlN layers were fabricated. AlN layer sputtered with 400 W under 40 to 60 vol%N2 at 773 K was grown by about 1 μm thickness. The AlN layer sputtered with 400 W under 40 and 50 vol%N2 at 573 and 773 K showed superior quality, with almost identical crystal structural quality to that of each nitrided sapphire substrate. (© 2011 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

半导体激光器腔面增透膜AlN薄膜的制备

The relationship between output power and reflectance of the cavity surface was simulated.Simulation results showed that,when the reflectance of cavity surface coatings took the optimum value,the output power of the semiconductor lasers diode reached the maximum.AlN film were deposited on K9 glass substrates by magnetron sputtering using high-purity Al target and N2+Ar.The influence of sputtering conditions,including working pressure,nitrogen concentration,sputtering power on its deposition rate and optical properties has been studied.The optimized AlN coating was used in semiconductor lasers,we found that the COD threshold and the output power have been greatly improved.

Influence of Sputtering Conditions on Structural and Electrochemical Properties of the Si Anode Film for Lithium Secondary Batteries

)Abstract This study investigated the dependence of the various sputtering conditions (Ar pressure:2~10 mTorr, Power: 50~150 W) and thickness (50~1200 nm) of Si thin film on the electrochemical properties,microstructural properties and the capacity fading of a Si thin film anode. A Si layer and a Ti buffer layerwere deposited on Copper foil by RF-magnetron sputtering. At 10 mTorr, the 50 W sample showed the bestcapacity of 3323 mAh/g, while the 100 W sample showed the best capacity retention of 91.7%, also at 10 mTorr.The initial capacities and capacity retention in the samples apart from the 50 W sample at 10 mTorr wereenhanced as the Ar pressure and power increased. This was considered to be related to the change of themicrostructure and the surface morphology by various sputtering conditions. In addition, thinner Si film anodesshowed better cycling performance. This phenomenon is caused by the structural stress and peeling off of theSi layer by the high volume change of Si during the charge/discharge process.Key wordslithium ion battery, silicon anode, deposition condition, sputtering.

The impact of sputter conditions on the microstructure and on the resistivity of tantalum thin films

In this work, the influence of sputter conditions and film thickness on both the morphology and the resistivity of tantalum (Ta) thin films will be investigated. Glass wafers were used as substrates. With increasing back pressure level ranging from 0.3 to 6 Pa at a fixed plasma power of 100 W, the microstructure changes from a dense to an open porous characteristics. At a moderate back pressure level of 0.9 Pa, the stable α-phase is detected when the film thickness exceeds a value of about 1.3 µm. Besides the impact of phase composition, the microstructure influences in addition the electrical performance of the Ta films. Therefore, the room-temperature resistivity can be varied within two orders of magnitude by applying different parameters for film deposition.

ＲＦ反応スパッタ法によるＡｌ‐Ｏ‐Ｎコーティング膜の作製

The influence of sputtering conditions on the microstructure and mechanical properties of Al-O-N films was investigated using XRD, TEM and nano-indentation. The targets of sintered Al2O3 plate were sputtered in a mixture of argon and nitrogen using an r.f. sputtering apparatus of facing target-type sputtering. Nitrogen gas flow rate was controlled from 0 to 40 sccm under the fixed Ar gas flow rate (10 sccm). The substrate was heated up to ∼300°C. The highest hardness of 27 GPa was obtained for the Al-O-N film deposited at 300°C under 30 sccm of the nitrogen gas flow rate, which value is almost twice that of Al-O films.XRD and SAED analysis of Al-O-N films suggested the existence of some phases; hcp-AlN, AlON and ι-Al2O3 phase may presented in the film. The dark-field TEM images of the Al-O-N films revealed that the film consists of very fine grains of ∼6 nm in diameter.The Al-O-N film having the highest hardness has higher transparency of visible light than that of Al-O films. Even if the Al-O-N films was annealed up to 800°C for 1 hour in the air, mechanical properties were not changed, but decreased drastically after the annealing at 900°C.