Reactive Magnetron Sputtering Method Research Articles

Effects of silicon nitride diffusion barrier on germanium MOS capacitors with HfON gate dielectrics

MOS capacitors with hafnium oxynitride (HfON) gate dielectrics were fabricated on Ge and Si substrates using the RF reactive magnetron sputtering method. A large amount of fixed charges and interface traps exist at the Ge/HfON interface. HRTEM and XPS analyses show that Ge oxides were grown and diffused into HfON after post metal annealing. A Si nitride interfacial layer was inserted between Ge and HfON as diffusion barrier. Using this method, well behaved capacitance-voltage and current-voltage characteristics were obtained. Finally hystereses are compared under different process conditions and possible causes are discussed.

증착 온도가 RF 반응성 마그네트론 스퍼터링법으로 성장된 InN 박막의 특성에 미치는 영향

Indium nitride thin films were deposited by the radio-frequency reactive magnetron sputtering method. The indium target was sputtered by the mixture flow ratio of <TEX>$N_2$</TEX> to Ar, 9:1. The effects of growth temperature on the structural, optical, and electrical properties of the films were investigated. With increasing the growth temperature, the crystallinity of the films was improved, and the crystalline size was increased. The energy bandgap for the film grown at <TEX>$25^{\circ}C$</TEX> was 3.63 eV, and the bandgap showed an increasing tendency on the growth temperature. The carrier concentration, Hall mobility and electrical resistivity of the films depended significantly on the growth temperature and the maximum Hall mobility of <TEX>$32.3\;cm^2$</TEX>/Vsec was observed for the film grown at <TEX>$400^{\circ}C$</TEX>.

Characterization of NbC coatings deposited by magnetron sputtering method

The paper presents the results obtained on the deposition and characterization of niobium carbide thin films obtained by reactive magnetron sputtering method in a reactive atmosphere composed by Ar and CH 4. The coatings were deposited on Si substrates, at 100 °C, 400 °C and 750 °C, at two different substrate bias values and five different CH 4/(Ar + CH 4) flow ratios. The films were analyzed for phase (XRD) and elemental (AES) compositions, surface morphology (AFM) and optical reflectivity in UV–VIS domain. X-ray analysis revealed that the coatings crystallized in either cubic or hexagonal structure, depending on the CH 4 relative abundance in the deposition atmosphere, independent of the substrate bias or deposition temperature. The films deposited at a lower substrate temperature were less crystallized and had significantly smaller mean grain sizes. The reflectivity values were found to depend on the films crystallographic structure, carbon content and amount of non-reacted metal. The films presented a low roughness, specific to films deposited by magnetron sputtering method.

Relation between the plasma characteristics and physical properties of functional zinc oxide thin film prepared by radio frequency magnetron sputtering process

The ZnO thin film was deposited on a glass substrate by a RF reactive magnetron sputtering method. Results showed that plasma density, electron temperature, deposition rate and estimated ion bombardment energy increase with increasing applied RF power. Three distinct power regimes were observed, which are strongly correlated with plasma properties. In the low-power regime, the largest grain size was observed due to slow deposition rate. In the medium-power regime, the smallest grain size was found, which is attributed to insufficient time for the adatoms to migrate on substrate surface. In the high-power regime, relatively larger grain size was found due to very large ion bombardment energy which enhances the thermal migration of adatoms. Regardless of pure ZnO thin film or ZnO on glass, high transmittance (> 80%) in the visible region can be generally observed. However, the film thickness plays a more important role for controlling optical properties, especially in the UV region, than the applied RF power. In general, with properly coated ZnO thin film, we can obtain a glass substrate which is highly transparent in the visible region, is of good anti-UV characteristics, and is highly hydrophobic, which is highly suitable for applications in the glass industry.

Photocatalytic activity of ZnO films with micro-grid structure

A layer of zinc oxide (ZnO) micro-grid was deposited on the surface of ZnO film using the DC reactive magnetron sputtering method and the micro-sphere lithography technique on glass substrates. Samples of this layer were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and ultraviolet-visible light spectroscopy. X-ray diffraction showed the high crystallinity of ZnO film and the regular arrangement of the micro-grid. The microgrid ZnO has a lower specular reflection and a higher diffuse reflection, allowing incident light to reflect two or three times to enhance the usage of light. Photocatalytic degradation experiments on methylene blue using both ZnO micro-grid and ordinary film showed that the ZnO micro-grid has better photo-catalytic properties than ordinary film. The ZnO micro-grid enhanced the photocatalytic efficiency of ZnO film by 28% with a degradation time of 300 min.

Yttrium-doped TiO 2 films prepared by means of DC reactive magnetron sputtering

Y 2O 3-doped TiO 2 films were prepared on glass substrates by means of pulsed DC reactive magnetron sputtering method using titanium and yttrium mixed target. XPS results showed that the films were composed of fully oxidation states of the two elements, Y 2O 3–TiO 2 composite oxides. The existence of yttrium inhibited the crystal growth of TiO 2 in the films and Y 2O 3 mainly presented in its amorphous state in the films. UV–vis transmittance of the films decreased whereas their reflectance increased slightly. Yttrium doping had detrimental effect on photocatalytic activity of the TiO 2 films. Photocatalytic degradation efficiency of methyl orange solution declined along with increasing yttrium concentration.

Growth of p-type ZnO films and fabrication of ZnO photodiode-based UV detectors

In this work, Al–N-co-doped ZnO films were deposited on the smooth nucleation side of a freestanding diamond film by a radio-frequency (RF) reactive magnetron sputtering method. The influence of sputtering atmosphere and substrate temperature on the conduction type of ZnO films was studied. ZnO photodiodes were fabricated by depositing the Al–N-co-doped p-type ZnO films on the Al-doped n-type ZnO films. The ZnO photodiode exhibited the distinct rectifying current–voltage (I–V) characteristics with a turn-on voltage of ∼2.0 V. The photodiode was used for UV detector application and the detector showed a significant discrimination between UV and the visible light.

Improvement of Field Emission Characteristics of Copper Nitride Films with Increasing Copper Content

A copper nitride (Cu3N) thin film is deposited on a Si substrate by the reactive magnetron sputtering method. The XPS measurements of the composite film indicate that the Cu content in the film is increased to 80.82 at. % and the value of the Cu/N ratio to 4.2:1 by introducing 4% H2 into the reactive gas. X-ray diffraction measurements show that the film is composed of Cu3N crystallites with an anti-ReO3 structure. The effects of the increase of copper content on the field emission characteristics of the Cu3N thin film are investigated. Significant improvement in emission current density and emission repeatability could be attributed to the geometric field enhancement, caused by numerous surface nanotips, and the decrease of resistivity of the film.

Effect of N content on phase configuration, nanostructure and mechanical behaviors in Ti–C x–N y thin films

Ti–C x –N y thin films with different nitrogen contents were deposited by way of incorporation of different amounts of nitrogen into TiC 1.02 using unbalanced reactive unbalanced dc magnetron sputtering method. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM) and microindentation methods were used to investigate their phase configurations, nanostructures and mechanical behaviors in order to investigate their dependences on nitrogen content. The result indicated that the nitrogen content had a significant effect on phase configuration, nanostructure and mechanical behaviors of Ti–C x –N y thin films. The nitrogen-free TiC 1.02 films exhibited a polycrystallite with nano-grains. On one hand, incorporated nitrogen substituted C in TiC 1.02, producing Ti(C,N), and subsequently linked to the substituted C, forming C–N. On the other hand, the substituted C lined to each other, forming C–C. As a result, nanocomposite thin films consisting of nanocrystalline Ti(C,N) and amorphous (C, C–N) were produced. With further incorporation of nitrogen more C was substituted, accompanying with formation of more amorphous matrices and decrease of size of nanocrystalline Ti(C,N). The trend was enhanced with further increase of nitrogen content. A microhardness maximum of ∼58 GPa was obtained in nitrogen-free TiC 1.02 thin films. This value was linearly decreased with incorporation of N or increase of N content, and finally a hardness value of about 28 GPa was followed at a N content of ∼25 at.%. Both elastic modulus and residual compressive stress values exhibited similar trends.

Surface properties of doped and undoped TiO 2 thin films deposited by magnetron sputtering

In this work, transparent titanium dioxide (TiO 2) thin films were deposited onto microscope glass slides by means of the d.c. reactive magnetron sputtering method. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV–visible spectroscopy (UV) and contact angle analysis using the Owens–Wendt method for the surface energy calculation. The photocatalytic activity of the films was tested by measuring the photodegradation of Rhodamine-B ( RhB) dye under radiation of UV light. Iron-doped TiO 2 films were also prepared in order to study the Fe-doping effect on TiO 2 photocatalytic activity. The influences of different iron concentrations on the contact angle of the series of Fe-doped TiO 2 thin films, were investigated. The influences of total sputtering pressures on TiO 2 photocatalytic activity were also investigated. It was observed that the photocatalytic activity of the TiO 2 thin films was slightly improved by increasing the total sputtering pressure. Moreover, it was also observed that in general, iron-doping was detrimental for photocatalytic activity, nevertheless the films with low iron concentrations showed better photocatalytic activity than those with high iron concentrations. It was found that iron-doping has changed the wettability appetency of TiO 2 coated surfaces.

Fabrication and electric characterization of the n-ZnO/ p-nanocrystalline diamond film heterojunction

A heterojunction of n-ZnO / p-nanocrystalline diamond (NCD) film was fabricated, where the undoped p-type NCD film and n-type ZnO film were grown by microwave plasma chemical vapor deposition (MPCVD) method and radio-frequency (RF) reactive magnetron sputtering method, respectively. The structure and morphology of the NCD film and ZnO film were analyzed by Raman spectroscopy, X-ray diffraction (XRD) and atomic force microscopy (AFM). The carrier sheet densities of p-type NCD film and n-type ZnO film measured by Hall Effect method were 1.3×1012 cm-2 and 8.9×1014 cm-2, respectively. I-V characterization of the n-ZnO / p-NCD heterojunction indicated that this structure was rectifying in nature with a turn-on voltage of about 0.6V.

PHOTO-CATALYTIC TRANSPARENT HEAT MIRROR FILM TiO2/TiN/TiO2

Transparenet heat mirror thin films, having high transmittance in the visible region and high reflectance in the infrared region. TiO/TiN/TiO2 films prepared D.C reactive magnetron sputtering method on glass substrates, play role as transparent heat mirror. Besides, the top TiO2 layer has both photo-catalytic and anti-reflective properties. However, st ong thickness dependence of top layer on catalytic properties is a problem need to solve. The experiment shows optimum thickness in order to have good catalytic properties is above 350 nm. This report, we found relationship among thicknesses of films through calculating and experiment. Films prepared, have both catalytic and transparent heat mirror properties with the bottom Tio, layer thickness of 40-300 nm, the middle TiN layer thickness of 16-22 nm and the top TiO2 layer of above 350 nm.

Functionality of Ti-O Thin Films Doped by Phosphorus: Wettability, Semiconductor Performance and Blood Compatibility

For an application as biomedical materials of high performance with a good biocompatibility, the Ti-O film on Si (110) wafer substrate has been synthesize by means of unbalance reactive magnetron sputtering method and modified by phosphorus ion implantation and succeeding vacuum annealing. X-ray diffraction (XRD) results indicated that such prepared Ti-O film had a rutile structure. X-ray photoelectron spectroscopy (XPS) analysis demonstrates the effect of P ion doping. The contact angle test and sheet resistance results showed that titanium oxide film and phosphorus-doped titanium oxide film became more hydrophilic and higher conductance after annealing. The morphology and roughness of the surface have been investigated using SEM. Antithrombotic property of the titanium oxide thin film was examined by platelet adhesion tests. The results showed that the undoped Ti-O films and the P implant and annealing at 900 °C Ti-O film had good blood compatibility.

Investigation of Characteristics of Multi-Function ZnO Thin Film Deposited with Various Argon and Oxygen Ratios

AbstractThe ZnO thin film was successfully deposited on a glass substrate at RT by a RF reactive magnetron sputtering method. Structural, chemical, optical, and hydrophilic/hydrophobic properties are measured by using a surface profilometer, an x-ray diffractometry (XRD), an x-ray photoelectron spectroscopy (XPS), a UV-VIS spectrophotometer, and a contact angle system, respectively. Results show that the deposition rate decreases with increasing O2/(Ar+O2) ratio. Otherwise, the best stoichiometric and quality of ZnO thin film was observed at 0.30 of O2/(Ar+O2) ratio by the smallest FWHM and the strong O-Zn bonds. Regardless of O2/(Ar+O2) ratio effect or thickness effect, high transmittance (&gt; 86%) in the visible region is observed, while the UV-shielding characteristics depend upon both the magnitude of film thickness. The film thickness plays a more prominent role in controlling optical properties, especially in the UV-shielding characteristics, than the O2/(Ar+O2) ratio. However, the hydrophobic characteristics can be obtained when the glass coating with ZnO thin films. In general, with properly coated ZnO thin film, we can obtain a glass substrate which is highly transparent in the visible region, has good UV-shielding characteristics, and possesses highly hydrophobic characteristics (self-clean capability), which is highly suitable for applications in the glass industries.

Terahertz transmission properties of transparent conducting molybdenum-doped ZnO films

With direct current reactive magnetron sputtering method，transparent conducting molybdenum-doped ZnO （ZMO） thin films with different carrier concentration on glass substrate were fabricated by monitoring oxygen partial pressure. The dielectric responses of the ZMO films are characterized with terahertz time-domain spectroscopy. Frequency dependent conductivity，power absorption，and refractive index are obtained，and the experimental results can be well reproduced with classic Drude model. Our results reveal that，by adjusting the carrier concentration of ZMO film，the conducting ZMO film can serve as broadband antireflection coatings for substrates and optics in terahertz frequency range.

Spectroscopic Ellipsometry Study on Surface Roughness and Optical Property of AZO Films Prepared by Direct-Current Magnetron Reactive Sputtering Method

All as-deposited AZO films by direct current magnetron reactive sputtering (DC-MS) exhibit ZnO characteristic (002) and (103) diffraction peaks. Especially, AZO films prepared at 200° C show a strongest (002) c-axis preferential orientation due to the minimum stress along the (002) orientation. The results show that larger stress easily induces a rougher surface. The film real and imaginary parts of dielectric constants show a sharp changes near the optical absorption edge due to the interband direct transition. The film blue and red shifts of the optical absorption edge can be explained in terms of the change of free-electron concentration in as-deposited AZO films.

Efficient degradation of aqueous methyl orange over TiO 2 and CdS electrodes using photoelectrocatalysis under UV and visible light irradiation

A highly efficient photoelectrocatalytic course was realized by combining TiO 2 and CdS films. The TiO 2 films were prepared using dc reactive magnetron sputtering method, and the CdS films were deposited by chemical bath deposition (CBD) method. The X-ray diffraction (XRD), Raman, field-emission scanning electron microscope (FESEM) were used to characterize the film structure and surface morphologies. The experiment results showed that the photoelectrocatalysis by using the TiO 2 and CdS films under double-beam irradiation of UV and visible lights had higher photocatalytic activity than the sum of photoelectrocatalysis solely using TiO 2 and CdS films.

Carrier concentration dependence of terahertz transmission on conducting ZnO films

With the dc reactive magnetron sputtering method, conducting ZnO thin films with different carrier concentrations on glass substrate were fabricated. The dielectric responses of the ZnO films are characterized with terahertz time-domain spectroscopy. Frequency-dependent conductivity, power absorption, and refractive index are obtained, and the experimental results can be well reproduced with the classic Drude model. Our results reveal that by adjusting the carrier concentration of the ZnO film, the conducting ZnO film can serve as broadband antireflection coatings for substrates and optics in the terahertz frequency range.

Narrow-band deep-ultraviolet light emitting device using Al1−xGdxN

We demonstrated mercury-free narrow-band deep-ultraviolet luminescence from field-emission devices with Al1−xGdxN thin films. The Al1−xGdxN thin films were grown on fused silica substrates by a radio frequency reactive magnetron sputtering method. The deposited film shows a strong c-axis preferential orientation. A resolution limited, narrow intra-4f luminescence line from Gd3+ ions has been observed at 315nm. The luminescence spectrum depends on the growth temperature of the thin film, and the intensity varies as a function of the GdN mole fraction.

Photocatalytic activities of amorphous TiO2-Cr thin films prepared by magnetron sputtering

Chrome-doped titanium oxide films were prepared by reactive magnetron sputtering method. The films deposited on glass slides at room temperature were investigated by atom force microscope, X-ray diffractometer, X-ray photoelectron spectroscopy, UV-Vis spectrophotometer, the photoluminescence (PL) and ellipse polarization apparatus. The results indicate that TiO2-Cr film exists in the form of amorphous. The prepared films possess a band gap of less than 3.20 eV, and a new absorption peak. The films, irradiated for 5 h under UV light, exhibit excellent photocatalytic activities with the optimum decomposition rate at 98.5% for methylene blue. Consequently, the thickness threshold on these films is 114 nm, at which the rate of photodegradation is 95% in 5 h. When the thickness is over 114 nm, the rate of photodegradation becomes stable. This result is completely different from that of crystalloid TiO2 thin film.