EFFECT OF Ar PRESSURE ON STRUCTURAL AND ELECTRICAL PROPERTIES OF Cu FILMS DEPOSITED ON GLASS BY DC MAGNETRON SPUTTERING

Cu films with thickness of 630-1300nm were deposited on glass substrates without heating by DC magnetron sputtering in pure Ar gas. Ar pressure was controlled to 0.5, 1.0 and 1.5Pa respectively. The target voltage was fixed at 500V but the target current increased from 200 to 1150mA with Ar pressure increasing. X-ray diffraction, scanning electron microscopy and atomic force microscopy were used to observe the structural characterization of the films. The resistivity of the films was measured using four-point probe technique. At all the Ar pressures, the Cu films have mixture crystalline orientations of [111], [200] and [220] in the direction of the film growth. The film deposited at lower pressure shows more [111] orientation while that deposited at higher pressure has more [220] orientation. The amount of larger grains in the film prepared at 0.5Pa Ar pressure is slightly less than that prepared at 1.0Pa and 1.5Pa Ar pressures. The resistivities of the films prepared at three different Ar pressures represent few differences, about 3-4 times of that of bulk material. Besides the deposition rate increases with Ar pressure because of the increase in target current. The contribution of the bombardment of energetic reflected Argon atoms to these phenomena is discussed.

Photocatalytic Property of TiO2 Films Deposited by Pulsed DC Magnetron Sputtering

TiO2 thin films were prepared by DC magnetron sputtering with the oxygen flow rate higher than the threshold. The film deposited for 5 h was of anatase phase with a preferred orientation along the <220> direction, but the films deposited for 2 and 3 h were amorphous. The transmittance and photocatalytic activity of the TiO2 films increased constantly with increasing film thickness. When the annealing temperature was lower than 700℃, only anatase grew in the TiO2 film. TiO2 phase changed from anatase to rutile when the annealing temperature was above 800℃. The photocatalytic activity decreased with increasing annealing temperature.

Indium–tin oxide films obtained by DC magnetron sputtering for improved Si heterojunction solar cell applications

The indium-tin oxide （ITO） film as the antireflection layer and front electrodes is of key importance to obtaining high efficiency Si heterojunction （HJ） solar cells. To obtain high transmittance and low resistivity ITO films by direct-current （DC） magnetron sputtering, we studied the impacts of the ITO film deposition conditions, such as the oxygen flow rate, pressure, and sputter power, on the electrical and optical properties of the ITO films. ITO films of resistivity of 4 x 10-4 ~.m and average transmittance of 89% in the wavelength range of 380-780 nm were obtained under the optimized conditions： oxygen flow rate of 0.1 sccm, pressure of 0.8 Pa, and sputtering power of 110 W. These ITO films were used to fabricate the single-side HJ solar cell without an intrinsic a-Si：H layer. However, the best HJ solar cell was fabricated with a lower sputtering power of 95 W, which had an efficiency of 11.47%, an open circuit voltage （Voc） of 0.626 V, a filling factor （FF） of 0.50, and a short circuit current density （Jsc） of 36.4 mA/cm2. The decrease in the performance of the solar cell fabricated with high sputtering power of 110 W is attributed to the ion bombardment to the emitter. The Voc was improved to 0.673 V when a 5 nm thick intrinsic a-Si：H layer was inserted between the （p） a-Si：H and （n） c-Si layer. The higher Voc of 0.673 V for the single-side HJ solar cell implies the excellent c-Si surface passivation by a-Si：H.

Reactive DC Magnetron Sputtering Deposition of Copper Nitride Thin Film

Copper nitride thin film was deposited on glass substrates by reactive DC （direct current） magnetron sputtering at a 0.5 Pa N2 partial pressure and different substrate temperatures. The as-prepared film, characterized with X-Ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy measurements, showed a composed structure of Cu3N crystallites with anti-ReO3 structure and a slight oxidation of the resulted film.The crystal structure and growth rate of Cu3N films were affected strongly by substrate temperature. The preferred crystalline orientation of Cu3N films were （111） and （200） at RT, 100℃. These peaks decayed at 200℃ and 300℃ only Cu （111） peak was noticed. Growth of Cu3N films at 100℃ is the optimum substrate temperature for producing high-quality （111） Cu3N films. The deposition rate of Cu3N films estimated to be in range of 18-30 nm/min increased while the resistivity and the microhardness of Cu3N films decreased when the temperature of glass substrate increased.

Deposition and characterization of TiZrV-Pd thin films by dc magnetron sputtering

TiZrV film is mainly applied in the ultra-high vacuum pipes of storage rings. Thin fihn coatings of palladium, which are added onto the TiZrV film to increase the service life of nonevaporable getters and enhance H2 pumping speed, were deposited on the inner face of stainless steel pipes by dc magnetron sputtering using argon gas as the sputtering gas. The TiZrV-Pd film properties were investigated by atomic force microscope （AFM）, scanning electron microscope （SEM）, X-ray photoelectron spectroscopy （XPS） and X-Ray Diffraction （XRD）. The grain size of TiZrV and Pd films were about 0.42 1.3 nm and 8.5-18.25 nm respectively. It was found that the roughness of TiZrV films is small, about 2 4 nm, but for Pd film it is large, about 17 19 nm. The PP At. % of Pd in TiZrV/Pd films varied from 86.84 to 87.56 according to the XPS test results.

Microstructure and Properties of the Cr–Si–N Coatings Deposited by Combining High-Power Impulse Magnetron Sputtering(HiPIMS) and Pulsed DC Magnetron Sputtering

The Cr–Si–N coatings were prepared by combining system of high-power impulse magnetron sputtering and pulsed DC magnetron sputtering. The Si content in the coating was adjusted by changing the sputtering power of the Si target.By virtue of electron-probe microanalysis, X-ray diffraction analysis and scanning electron microscopy, the influence of the Si content on the coating composition, phase constituents, deposition rate, surface morphology and microstructure was investigated systematically. In addition, the change rules of micro-hardness, internal stress, adhesion, friction coefficient and wear rate with increasing Si content were also obtained. In this work, the precipitation of silicon in the coating was found.With increasing Si content, the coating microstructure gradually evolved from continuous columnar to discontinuous columnar and quasi-equiaxed crystals; accordingly, the coating inner stress first declined sharply and then kept almost constant. Both the coating hardness and the friction coefficient have the same change tendency with the increase of the Si content, namely increasing at first and then decreasing. The Cr–Si–N coating presented the highest hardness and average friction coefficient for an Si content of about 9.7 at.%, but the wear resistance decreased slightly due to the high brittleness.The above phenomenon was attributed to a microstructural evolution of the Cr–Si–N coatings induced by the silicon addition.

Photoelectric properties of ITO thin films deposited by DC magnetron sputtering

As anti-reflecting thin films and transparent electrodes of solar cells, indium tin oxide （ITO） thin films were prepared on glass substrates by DC magnetron sputtering process. The main sputtering conditions were sputtering power, substrate temperature and work pressure. The influence of the above sputtering conditions on the transmittance and conductivity of the deposited ITO films was investigated. The experimental results show that, the transmittance and the resistivity decrease as the sputtering power increases from 30 to 90 W. When the substrate temperature increases from 25 to 150℃, the transmittance increases slightly whereas the resistivity decreases. As the work pressure increases from 0.4 to 2.0 Pa, the transmittance decreases and the resistivity increases. When the sputtering power, substrate temperature and work pressure are 30 W, 150℃, 0.4 Pa respectively, the ITO thin films exhibit good electrical and optical properties, with resistivity below 10^-4 Ωcm and the transmittance in the visible wave band beyond 80%. Therefore, the ITO thin films are suitable as transparent electrodes of solar cells.

Effect of N_2-Gas Partial Pressure on the Structure and Properties of Copper Nitride Films by DC Reactive Magnetron Sputtering

Copper nitride thin films were deposited on glass substrates by reactive direct current （DC） magnetron sputtering at various N2-gas partial pressures and room temperature. Xray diffraction measurements showed that the films were composed of Cu3N crystallites and exhibited a preferential orientation of the [111] direction at a low nitrogen gas （N2） partial pressure. The film growth preferred the [111] and the [100] direction at a high N2 partial pressure. Such preferential film growth is interpreted as being due to the variation in the Copper （Cu） nitrification rate with the N2 pressure. The N2 partial pressure affects not only the crystal structure of the film but also the deposition rate and the resistivity of the Cu3N film. In our experiment, the deposition rate of Cu3N films was 18 nm/min to 30 nm/min and increased with the N2 partial pressure. The resistivity of the Cu3N films increased sharply with the increasing N2 partial pressure. At a low N2 partial pressure, the Cu3N films showed a metallic conduction mechanism through the Cu path, and at a high N2 partial pressure, the conductivity of the Cu3N films showed a semiconductor conduction mechanism.

Influences of working pressure on properties for TiO_2 films deposited by DC pulse magnetron sputtering

TiO2 films were deposited at room temperature by DC pulse magnetron sputtering system.The crystalline structures,morphological features and photocatalytic activity of TiO2 films were systematically investigated by X-ray diffraction（XRD）,atomic force microscopy（AFM） and ultraviolet spectrophotometer,respectively.The results indicated that working pressure was the key deposition parameter in？uencing the TiO2 film phase composition at room temperature,which directly affected its photocatalytic activity.With increasing working pressure,the target self-bias decreases monotonously.Therefore,low temperature TiO2 phase（anatase） could be deposited with high working pressure.The anatase TiO2 films deposited with 1.4 Pa working pressure displayed the highest photocatalytic activity by the decomposition of Methyl Orange solution,which the degradation rate reached the maximum（35%） after irradiation by ultraviolet light for 1 h.

OPTICAL CHARACTERIZATION OF TiO_2 THIN FILM ON SILICON SUBSTRATE DEPOSITED BY DC REACTIVE MAGNETRON SPUTTERING

TiO2 thin film has attracted considerable attention in recent years, due to its different refractive index and transparency with amorphous and different crysta ls in the visible and near-infrared wavelength region, high dielectric constant, wide band gap, high wear resistance and stability, etc, for which make it being used in many fields. This paper aims to investigate the optical characterizatio n of thin film TiO2 on silicon wafer. The TiO2 thin films were prepared by DC re active magnetron sputtering process from Ti target. The reflectivity of the film s was measured by UV-3101PC, and the index of refraction (n) and extinction coef ficient (k) were measured by n & k Analyzer 1200.

Investigation of High Catalyteal Durability for Porous Pt Films Deposited via Magnetron Sputtering

Porous Pt thin films were prepared on carbon papers by a single-step ultra-high dc magnetron sputtering method to obtain ideal electrodes for proton exchange membrane fuel cells.The platinum loading of the electrocatalyst layer is controlled at about 0.1 mg·cm^(-2).Structural characteristics and catalytic activities of the films were analyzed by scanning electron microscopy,atomic force microscopy,X-ray diffraction,cyclic voltammetry,and stress durability testing methods.The effect of treatment conditions of a substrate on the structural and performance characteristics of the catalytic films was shown as well.Films produced on acid-treated carbon papers at the argon pressure of 0.01 mbar possessed a homogeneous,highly developed surface along with a porous structure.Compared to Pt/TCPW(Toray carbon papers soaked in ultrapure water)electrodes,the film obtained on the acid-treated substrate had a larger electrochemical surface area(163.33 m^(2)·g^(-1))and exhibited better catalytic stability and durability due to a porous structure as a result of Pt particle accumulation.

THE EFFECTS OF SPUTTERING POWER ON STRUCTURE AND ELECTRICAL PROPERTIES OF Cu FILMS

Cu films with thickness of about 500nm were deposited on glass substrateswithout heating by DC magnetron sputtering in pure Ar gas of 1.0Pa. The sputtering powers weremaintained at 390V X 0.27A, 430V X 0.70A and 450V X l.04A, and the corresponding deposition rates ofCu film reached 35nm/min, l04nm/min and 167nm/min. X-ray diffraction, scanning electron microscopyand atomic force microscopy were used to observe the structural characteristics of the films. Theresistance of the films was measured using four-point probe technique. The amount of larger grainsincreases and the resistivity of the films decreases evidently with an increase in sputtering power.It is considered that the increase in deposition rate with sputtering power mainly weakens theinfluence of residual gas atoms on the growing film, and increases substrate and gas temperatures,resulting in the increase in grain size and the decrease in resistivity of the Cu film.

Insights into the oxidation resistance mechanism and tribological behaviors of multilayered TiSiN/CrVxN hard coatings

In the last decades,vanadium alloyed coatings have been introduced as potential candidates for self-lubrication due to their perfect tribological properties.In this work,the influence of V incorporation on the wear performance and oxidation resistance of TiSiN/CrN film coatings deposited by direct current(DC)reactive magnetron sputtering is investigated.The results show that vanadium incorporation significantly decreases the oxidation resistance of the coatings.In general,two layers are formed during the oxidation process:i)Ti(V)O_(2) on top,followed by a protective layer,which is subdivided into two layers,Cr_(2)O_(3) and Si-O.ii)The diffusion of V controls the oxidation of V-containing coatings.The addition of vanadium improves the wear resistance of coatings,and the wear rate decreases with increasing V content in the coatings;however,the friction coefficient is independent of the chemical composition of the coatings.The wear of the V-containing coatings is driven by polishing wear.

Preparation and characterization of single(200)-oriented TiN thin films deposited by DC magnetron reactive sputtering

Single(200)-oriented TiN thin films were deposited on quartz substrate by direct current(DC) magnetron reactive sputtering process at a wide range of substrate temperature from 200 to 600 ℃.The effects of sputtering pressure and substrate temperature on the crystalline nature,morphology,electrical and optical properties of the deposited thin films were analyzed by X-ray diffraction(XRD),atomic force microscopy(AFM),four-point resistivity test system and ultraviolet visible near-infrared(UV-Vis-NIR) spectroscopy,respectively.The results show that single(200)-oriented TiN thin films can be obtained at a wide range of substrate temperature from 200 to 600 ℃ with the grain size increasing from 35.9 to 64.5 nm.The resistivity of the product is as low as95 μΩ·cm,and the value of the optical reflectance is above68 % in the near-infrared(NIR) range of 760-1500 nm.

Carbon-Doped Titanium Oxide Films by DC Reactive Magnetron Sputtering Using CO_2 and O_2 as Reactive Gas

CO2 and O2 were employed as reactive gases to fabricate carbon-doped titanium oxide films using DC reactive magnetron sputtering. Microstructure, composition and optical band gap of the films were investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and UV-visible spectrophotometer, respectively. The results showed that carbon-doped titanium monoxide films （C-TiO） with a carbon concentration of 5.8 at.% were obtained in an AffCO2 mixed atmosphere. However, carbon-doped futile and anatase （C-TiO2） with a carbon concentration of about 1.4 at.% were obtained in an Ar/CO2/O2 mixed atmosphere. The optical band gaps of C-TiO and C-TiO2 were about 2.6 and 2.9 eV, respectively. Both of them were narrower than that of pure TiO2 films. Films with narrowed optical band gap energy are promising in promoting their photo-catalytic activity.

Influence of Nitrogen Flow Ratio on the Microstructure, Composition, and Mechanical Properties of DC Magnetron Sputtered Zr-B-O-N Films

Nanocrystalline ZrB2 film and nanocomposite Zr-B-O-N films were prepared by non-reactive as well as re- active magnetron sputtering techniques, respectively. By means of X-ray diffraction analysis, electron probe microanalysis, X-ray photoelectron spectroscopy, and scanning electron microscopy, the influence of nitrogen flow ratio on the film microstructure and characteristics were investigated systematically, including the depo- sition rate, chemical compositions, phase constituents, grain size, chemical bonding, as well as cross-sectional morphologies. Meanwhile, the hardness and adhesion of above films were also evaluated by micro-indentation method and a scratch tester. With increasing the nitrogen flow ratio, the deposition rate of above films de- creased approximately linearly, whereas the contents of N and O in the films increased gradually and tended to saturation. Moreover, the film microstructure was also altered gradually from a fine columnar microstructure to a featureless glass-structure. As the nitrogen flow ratio was 11.7%, the Zr-B-O-N film possessed an typical nanocomposite structure and presented good mechanical properties. During the process of reactive sputtering of metal borides, the introduction of nitrogen can show a pronounced suppression of columnar grain growth and strong nanocomposite structure forming ability.

SYNTHESIS AND THERMAL STABILITY OF NANOCOMPOSITE nc-TiN/a-TiB_2 THIN FILMS

Several nc-TiN/a-TiB2 thin films comprised of nanocrystalline (nc-) TiN and amor phous (a-) TiB2 phases were deposited on Si(100) at room temperature by reactive unbalanced dc magnetron sputtering, followed by vacuum annealed at 400, 600, 80 0 and 1000℃ for 1h, respectively. Effects of B content on microstructure, mecha nical behaviors and thermal microstructure stability have been investigated by X -ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and nanoindentation measurements. The results indicated that B addition greatly affected both microstructure and mechanical behavior of nc-Ti N/a-TiB2 thin films. With increasing B content the grain size decreased. A maxim um hardness value of about 33GPa was obtained at B content of about 19at.%. The improved mechanical properties of nc-TiN/a-TiB2 films with the addition of B int o TiN were attributed to their densified microstructure with development of fine grain size. Only addition of sufficient B could restrain grain growth during an nealing. High B content resulted in high microstructure stability. The crystalli zation of amorphous matrix occurred at about 800℃, forming TiB or TiB2 crystall ite, depending on B content. Before that no change in bonding configuration was found.