Preparation and Properties of Cu-Containing High-entropy Alloy Nitride Films by Magnetron Sputtering on Titanium Alloy

Magnetron sputtering deposition with regulated Cu target power was used for depositing Cu-containing high-entropy alloy nitride(Cu-(HEA)N)films on TC4 titanium alloy substrates.The microscopic morphologies,surface compositions,and thicknesses of the films were characterized using SEM+EDS;the anti-corrosion,wear resistance and antibacterial properties of the films in simulated seawater were investigated.The experimental results show that all four Cu-(HEA)N films are uniformly dense and contained nanoparticles.The film with Cu doping come into contact with oxygen in the air to form cuprous oxide.The corrosion resistance of the(HEA)N film without Cu doping on titanium alloy is better than the films with Cu doping.The Cu-(HEA)N film with Cu target power of 16 W shows the best wear resistance and antibacterial performance,which is attributed to the fact that Cu can reduce the coefficient of friction and exacerbate corrosion,and the formation of cuprous oxide has antibacterial properties.The findings of this study provide insights for engineering applications of TC4 in the marine field.

La-doped Copper Nitride Films Prepared by Reactive Magnetron Sputtering

Copper nitride film （Cu3N） and La-doped copper nitride films （LaxCu3N） were prepared on glass substrates by reactive magnetron sputtering of a pure Cu and a pure La targets under N2 atmosphere. The results show that La-free film was composed of Cu3N crystallites with anti-ReO3 structure with （111） texture. The formation of the LaxCu3N films is affected strongly by La, and the peak intensity of the preferred crystalline [111]-orientation decreases with increasing the concentration of La. High concentration of La may prevent the formation of the Cu3N from crystallization. Compared with the Cu3N films, the resistivity of the LaxCu3N films have been decreased.

Properties of Al-doped Copper Nitride Films Prepared by Reactive Magnetron Sputtering

Cu3N and Al Cu3N films were prepared with reactive magnetron sputtering method. The two films were deposited on glass substrates at 0.8 Pa N2 partial pressure and 100 ℃ substrate temperature by using a pure Cu and AI target, respectively. X-ray diffraction （XRD） measurements show that the un-doped film was composed of Cu3N crystallites with anti-ReO3 structure and adopted [111] preferred orientation. XRD shows that the growth of Al-doped copper nitride films （AlxCu3N） was affected strongly by doping AI, the intensity of [111] peak decreases with increasing the concentration of Al and the high concentration of Al could prevent the Cu3N from crystallization. AFM shows that the surface of AlCu3N film is smoother than that of Cu3N film. Compared with the Cu3N films, the resistivities of the Al-doped copper nitride films （AlxCu3N） have been reduced, and the microhardness has been enhanced.

The Adhesion Improvement of Cubic Boron Nitride Film on High Speed Steel Substrate Implanted by Boron Element

Cubic boron nitride(c-BN) films were deposited on W6Mo5Cr4V2 high speed steel(HSS) substrate implanted with boron ion by RF-magnetron sputtering. The films were analyzed by the bending beam method, scratch test, XPS and AFM. The experimental results show that the implantation of boron atom can reduce the internal stress and improve the adhesion strength of the films. The critical load of scratch test rises to 27.45 N, compared to 1.75 N of c-BN film on the unimplanted HSS. The AFM shows that the surface of the c-BN film on the implanted HSS is low in roughness and small in grain size. Then the composition of the boron implanted layer was analyzed by the XPS. And the influence of the boron implanted layer on the internal stress and adhesion strength of c-BN films were investigated.

Effect of hydrogen content on dielectric strength of the silicon nitride film deposited by ICP-CVD

The inductively coupled plasma chemical vapor deposition(ICP-CVD) deposited silicon nitride(SiN_(x)) thin film was evaluated for its application as the electrical insulating film for a capacitor device.In order to achieve highest possible dielectric strength of SiN_(x),the process parameters of ICP-CVD were carefully tuned to control hydrogen in SiN_(x) films by means of tuning N_(2)/SiH_(4) ratio and radio frequency(RF) power.Besides electrical measurements,the hydrogen content in the films was measured by dynamic secondary ion mass spectrometry(D-SIMS).Fourier transform infrared spectroscopy(FTIR) and micro Raman spectroscopy were used to characterize the SiN_(x) films by measuring Si-H and N-H bonds’ intensities.It was found that the more Si-H bonds lead to the higher dielectric strength.

Nitridation Kinetics of Silicon Monocrystal and Morphology of Nitride Film

Basing on TGA (thermal gravimetric analysis) of thermal nitridation at l200, l250, l300℃, respectively, analysis of high temperature kinetics for nitridation of silicon monocrystal has been carried out. According to the theory for kinetics of reaction of vapour with solid phase a nitridation kinetic model, from which it can be shown thal the rate of nitridation reaction of silicon crystal should be controlled by three stage limiting factors, was proposed. These limiting factors are chemical reaction, chemical reaction mixed with diffusion and diffu- sion. Using this model to treat our experimental data, satisfactory correlation coefficient and apparent activation energy of nitridation of p-type (lll) silicon crystal have been obtained. The nitride film was identi' fied to be a-Si_3N_4 (Hexagonal, a=0.7758nm,c_o=0.5623nm) by X-ray diffraction analysis. Morphology of the nitride films formed in different nitridation duration was observed in both planar andcross-sectional views by SEM (scanning electron microscope).

Effect of applied dc bias voltage on composition, chemical bonding and mechanical properties of carbon nitride films prepared by PECVD

Carbon nitride films were deposited on Si (100) substrates using plasma-enhanced chemical vapor deposition (PECVD) technique from CH4 and N2 at different applied dc bias voltage. The microstructure, composition and chemical bonding of the resulting films were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The mechanical properties such as hardness and elastic modulus of the films were evaluated using nano-indentation. As the results, the Raman spectra, showing the G and D bands, indicate the amorphous structure of the films. XPS and FTIR measurements demonstrate the existence of various carbon-nitride bonds in the films and the hydrogenation of carbon nitride phase. The composition ratio of N to C, the nano-hardness and the elastic modulus of the carbon nitride films increase with increasing dc bias voltage and reach the maximums at a dc bias voltage of 300 V, then they decrease with further increase of the dc bias voltage. Moreover, the XRD analyses indicate that the carbon nitride film contains some polycrystalline C3N4 phase embedded in the amorphous matrix at optimized deposition condition of dc bias voltage of 300 V.

High Resolution Electron Microscopy Observations of Structural Changes in Iron Nitride Films Annealed in Vacuum

Iron-nitride films were prepared by reactive sputtering, and the effect of annealing treatment on the structures was investigated by means of in-situ electron microscopy and high resolution electron microscopy (HREM). As-deposited films were observed to be a mixed structure of a few ultrafine epsilon-Fe2-3N particles existing in the amorphous matrix. it was found that the structure-relaxation in the amorphous occurred at 473 K, and the ultrafine grains began to grow at the higher annealing temperatures. The transition of the amorphous to epsilon-Fe2-3N was almost completed at 673 K. It is considered that the formation of the ideal epsilon-Fe3N is originated from the ordering of the nitrogen atoms during the annealing in vacuum. On the other hand, gamma'-phase (Fe4N) was seen to precipitation of epsilon-phase at 723 K. Two possible modes are proposed in the precipitation of gamma'-phase, depending on the heating rate and crystallographic orientation relationships, i.e. [121](epsilon)//[001](gamma), (2(1) over bar0$)(epsilon)//(110)(gamma) and [100](epsilon)//[110](gamma), (001)(epsilon)//(111)(gamma). In addition, alpha-Fe particles were observed to form from the gamma'-phase at high temperatures. We assumed that these structural changes are due to the diffusion of nitrogen and iron atoms during the annealing, except for the case of the precipitation of the gamma'-phase as depicted above. The results obtained in this work are in a good agreement with the assumption.

Tailoring the microstructure,mechanical and tribocorrosion performance of (CrNbTiAlV)N_(x) high-entropy nitride films by controlling nitrogen flow

The(CrNbTiAlV)N_(x)high-entropy nitride films were fabricated by adjusting nitrogen flow via magnetron sputtering.The microstructure,mechanical,electrochemical and tribocorrosion performances of the films were studied.The results show that the films transform from amorphous to nanocrystalline structure as nitrogen flow increased.The nanocrystalline films show super hardness(>40 GPa)and adhesion strength(>50 N).The amorphous film has a pretty anti-corrosion in static corrosion,while not in tribocorrosion condition.The film deposited at nitrogen flow of 38 sccm exhibits the optimal tribocorrosion performance in artificial seawater,with the highest open circuit potential(∼−0.1 V vs.Ag/AgCl),the lowest friction coefficient(∼0.162)and wear rate(∼7.48×10^(−7)mm^(3)N^(−1)m^(−1)).

Optical properties of hexagonal boron nitride thin films deposited by radio frequency bias magnetron sputtering

The optical properties of hexagonal boron nitride （h-BN） thin films were studied in this paper. The films were characterized by Fourier transform infrared spectroscopy, UV-visible transmittance and reflection spectra, h-BN thin films with a wide optical band gap Eg （5.86 eV for the as-deposited film and 5.97 eV for the annealed film） approaching h-BN single crystal were successfully prepared by radio frequency （RF） bias magnetron sputtering and post-deposition annealing at 970 K. The optical absorption behaviour of h-BN films accords with the typical optical absorption characteristics of amorphous materials when fitting is made by the Urbach tail model. The annealed film shows satisfactory structure stability. However, high temperature still has a significant effect on the optical absorption properties, refractive index n, and optical conductivity σ of h-BN thin films. The blue-shift of the optical absorption edge and the increase of Eg probably result from stress relaxation in the film under high temperatures. In addition, it is found that the refractive index clearly exhibits different trends in the visible and ultraviolet regions. Previous calculational results of optical conductivity of h-BN films are confirmed in our experimental results.

Thermal conductivity of PECVD silicon-rich silicon nitride films measured with a SiO_2/Si_xN_y bimaterial microbridge test structure

In order to balance the compressive stress of a silicon dioxide film and compose a steady MEMS structure, a silicon-rich silicon nitride film with tensile stress is deposited by plasma enhanced chemical vapor deposition process. Accurately measuring the thermal conductivity of the film is highly desirable in order to design, simulate and optimize MEMS devices. In this paper, a Si02/SixNy bimaterial microbridge structure is presented to measure the thermal conductivity of the silicon-rich silicon nitride film by single steady-state measurement. The thermal conductivity is extracted as 3.25 W/（m-K）. Low thermal conductivity indicates that the silicon-rich silicon nitride film can still be utilized as thermally insulating material in thermal sensors although its thermal conductivity is slightly larger than the values reported in literature.

In situ infrared spectroscopic study of cubic boron nitride thin film delamination

This paper investigates the procedure of cubic boron nitride （cBN） thin film delamination by Fourier-transform infrared （IR） spectroscopy. It finds that the apparent IR absorption peak area near 1380cm^-1 and 1073 cm^-1 attributed to the B-N stretching vibration of sp2-bonded BN and the transverse optical phonon of cBN, respectively, increased up to 195% and 175% of the original peak area after film delamination induced compressive stress relaxation. The increase of IR absorption of sp2-bonded BN is found to be non-linear and hysteretic to film delamination, which suggests that the relaxation of the turbostratic BN （tBN） layer from the compressed condition is also hysteretic to film delamination. Moreover, cross-sectional transmission electron microscopic observations revealed that cBN film delamination is possible from near the aBN（amorphous BN）/tBN interface at least for films prepared by plasma-enhanced chemical vapour deposition.

Studies on Wear and Corrosion Resistances of Carbon Nitride Thin Films on Ti Alloy

CN x /SiCN composite films were prepared on titanium ( Ti ) alloy substrates by Radio Frequency Plasma Enhanced Chemical Vapor Deposition ( RF\|PECVD ). As a buffer layer, SiCN ensured the adhesion of the CN x thin films on Ti substrates. X\|ray diffraction ( XRD) measurement revealed that the composite films possessed α\|C 3 N 4 structure. The microhardness of the films was 48 to 50 GPa. In order to test the characteristics of wear and corrosion resistances, we prepared Ti alloy samples with and without CN x /SiCN composite films. Also for strengthening the effect of wear and corrosion, the wear tests were carried out under high load (12 MPa) and in 0.9% NaCl solution. Results of the wear tests and the corrosive electrochemical measurements showed that the samples coated with CN x films had excellent characteristics of wear and corrosion resistances compared with Ti alloy substrate samples.

Influence of oxygen on the growth of cubic boron nitride thin films by plasma-enhanced chemical vapour deposition

Cubic boron nitride thin films were deposited on silicon substrates by low-pressure inductively coupled plasmaenhanced chemical vapour deposition. It was found that the introduction of 02 into the deposition system suppresses both nucleation and growth of cubic boron nitride. At a B2H6 concentration of 2.5% during film deposition, the critical O2 concentration allowed for the nucleation of cubic boron nitride was found to be less than 1.4%, while that for the growth of cubic boron nitride was higher than 2.1%. Moreover, the infrared absorption peak observed at around 1230- 1280 cm^-1, frequently detected for cubic boron nitride films prepared using non-ultrahigh vacuum systems, appears to be due to the absorption of boron oxide, a contaminant formed as a result of the oxygen impurity. Therefore, the existence of trace oxygen contamination in boron nitride films can be evaluated qualitatively by this infrared absorption peak.

Effect of Hydrogen Dilution on Growth of Silicon Nanocrystals Embedded in Silicon Nitride Thin Film by Plasma-Enhanced CVD

An investigation was conducted into the effect of hydrogen dilution on the microstructure and optical properties of silicon nanograins embedded in silicon nitride （Si/SiNx） thin film deposited by the helicon wave plasma-enhanced chemical vapour deposition technique. With Ar-diluted SiH4 and N2 as the reactant gas sources in the fabrication of thin film, the film was formed at a high deposition rate. There was a high density of defect at the amorphous silicon （a-Si）/SiNx interface and a relative low optical gap in the film. An addition of hydrogen into the reactant gas reduced the film deposition rate sharply. The silicon nanograins in the SiNx matrix were in a crystalline state, and the density of defects at the silicon nanocrystals （nc-Si）/SiNx interface decreased significantly and the optical gap of the films widened. These results suggested that hydrogen activated by the plasma could not only eliminate in the defects between the interface of silicon nanograins and SiNx matrix, but also helped the nanograins transform from the amorphous into crystalline state. By changing the hydrogen dilution ratio in the reactant gas sources, a tunable band gap from 1.87 eV to 3.32 eV was obtained in the Si/SiNx film.

Deposition of Silicon Nitride Films by Silane Hydrazine Process

A new catalytic chemical vapor process for depositing silicon nitride films using silane hydrazine gaseous mixture is described. This system can be useful at a temperature of lower than 400 ℃. The catalytic process gives more rapid deposition rate than 10 nm/min. The atomic composition ratio, N/Si, which is evaluated by Rutherfold backscattering method is about 1.4 under a given experimental conditions more than the stoichiometric value of 1.33 in Si 3N 4. The infrared transmission spectra show a large dip at 850 cm -1 due to Si-N bonds and no clear dip due to Si-O bonds. High N-H bond density is the evidence that the deposition mechanism is limited by N-N bond breaking of the hydrazine. The H contents, evaluated from Si-H and N-H bonds in the infrared absorption spectra, and the deposition rate are measured as a function of the substrate temperature. In addition some film properties such as the resistivity and the breakdown electric field are presented.

Deposition of hexagonal boron nitride thin films on silver nanoparticle substrates and surface enhanced infrared absorption

Silver nanoparticle thin films with different average particle diameters are grown on silicon substrates. Boron nitride thin films are then deposited on the silver nanoparticle interlayers by radio frequency （RF） magnetron sputtering. The boron nitride thin films are characterized by Fourier transform infrared spectra. The average particle diameters of silver nanoparticle thin films are 126.6, 78.4, and 178.8 nm. The results show that the sizes of the silver nanoparticles have effects on the intensities of infrared spectra of boron nitride thin films. An enhanced infrared absorption is detected for boron nitride thin film grown on silver nanoparticle thin film. This result is helpful to study the growth mechanism of boron nitride thin film.

Experimental Observation of Cubic C_3N_4 Compound in Carbon Nitride Thin Films

Cubic C3N4 compound in the C-N thin films on Si and NaCl substrates was prepared by ion beam sputtering of a pure graphite target with discharge gas of pure N2. X-ray photoelectron spectroscopy indicated that nitrogen atoms combined with sp2- and sp3- coordinated C atoms in the film, respectively. X-ray diffraction, selected area electron diffraction and high-resolution electron microscopy were used to identify the cubic C3N4 phase. The results reconfirm the ab initio calculations on metastable structure in C-N compounds

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.

Structural,Morphological and Electrical Properties of In-Doped Zinc Oxide Nanostructure Thin Films Grown on p-Type Gallium Nitride by Simultaneous Radio-Frequency Direct-Current Magnetron Co-Sputtering

Zinc oxide （ZnO） is one of the most promising and frequently used semiconductor materials. In-doped nanos- tructure ZnO thin films are grown on p-type gallium nitride substrates by employing the simultaneous rf and dc magnetron co-sputtering technique. The effect of In-doping on structural, morphological and electrical properties is studied. The different dopant concentrations are accomplished by varying the direct current power of the In target while keeping the fixed radio frequency power of the ZnO target through the co-sputtering deposition technique by using argon as the sputtering gas at ambient temperature. The structural analysis confirms that all the grown thin films preferentially orientate along the c-axis with the wurtzite hexagonal crystal structure without having any kind of In oxide phases. The presenting Zn, 0 and In elements＇ chemical compositions are identified with EDX mapping analysis of the deposited thin films and the calculated M ratio has been found to decrease with the increasing In power. The surface topographies of the grown thin films are examined with the atomic force microscope technique. The obtained results reveal that the grown film roughness increases with the In power. The Hall measurements ascertain that all the grown films have n-type conductivity and also the other electrical parameters such as resistivity,mobility and carrier concentration are analyzed.