Effects of power on ion behaviors in radio-frequency magnetron sputtering of indium tin oxide(ITO)

This study delves into ion behavior at the substrate position within RF magnetron discharges utilizing an indium tin oxide(ITO)target.The positive ion energies exhibit an upward trajectory with increasing RF power,attributed to heightened plasma potential and initial emergent energy.Simultaneously,the positive ion flux escalates owing to amplified sputtering rates and electron density.Conversely,negative ions exhibit broad ion energy distribution functions(IEDFs)characterized by multiple peaks.These patterns are clarified by a combination of radiofrequency oscillation of cathode voltage and plasma potential,alongside ion transport time.This elucidation finds validation in a one-dimensional model encompassing the initial ion energy.At higher RF power,negative ions surpassing 100 e V escalate in both flux and energy,posing a potential risk of sputtering damages to ITO layers.

Facile integration of an Al-rich Al_(1-x)In_(x)N photodetector on free-standing GaN by radio-frequency magnetron sputtering

Al_(1-x)In_(x)N, a Ⅲ-nitride semiconductor material, is currently of great research interest due to its remarkable physical properties and chemical stability. When the Al and In compositions are tuned, its band-gap energy varies from 0.7 eV to 6.2 eV, which shows great potential for application in photodetectors. Here, we report the fabrication and performance evaluation of integrated Al_(1-x)In_(x)N on a free-standing GaN substrate through direct radio-frequency magnetron sputtering.The optical properties of Al_(1-x)In_(x)N will be enhanced by the polarization effect of a heterostructure composed of Al_(1-x)In_(x)N and other Ⅲ-nitride materials. An Al_(1-x)In_(x)N/Ga N visible-light photodetector was prepared by semiconductor fabrication technologies such as lithography and metal deposition. The highest photoresponsivity achieved was 1.52 A·W^(-1)under 365 nm wavelength illumination and the photodetector was determined to have the composition Al0.75In0.25N/GaN.A rise time of 0.55 s was observed after transient analysis of the device. The prepared Al_(1-x)In_(x)N visible-light photodetector had a low dark current, high photoresponsivity and fast response speed. By promoting a low-cost, simple fabrication method,this study expands the application of ternary alloy Al_(1-x)In_(x)N visible-light photodetectors in optical communication.

Characterization of La-doped xBiInO_3(1-x)PbTiO_3 Piezoelectric Films Deposited by the Radio-Frequency Magnetron Sputtering Method

La-doped and undoped xBiIn03-（1 - x）PbTi03 （BI-PT） thin films are deposited on （101）SrRuO3/（lOO）Pt/（lO0） MgO substrates by the rf-magnetron sputtering method. The structures of the films are characterized by XRD and SEM, and the results indicate that the thin films are grown with mainly （100） oriented and columnar structures. The ferroelectricity and piezoelectricity of the BI-PT films are also measured, and the measured results illustrate that both performances are effectively improved by the La-doping with suitable concentrations. These results will open up wide potential applications of the films in electronic devices.

Preparation of Indium Tin Oxide Films on Polycarbonate substrates by Radio-frequency Magnetron Sputtering

Indium tin oxide（ITO）thin films（100±10nm）were deposited on PC（polycarbonate）and glass substrates by rf（radio-frequency）mannetron spuutering.The oxygen content of the ITO films was changed by variation of the sputtering gas composition.All the other deposition parameters were kept constant.The sheet resistance.optical transmittance and microstructure of ITO films were investigated using a four-point probe.spectrophotometer,X-ray diffractometer（XRD）and atomic force microscope（AFM）.Sheet resistances for the ITO films with optical transmittance more than 75% on PC substrates varied from 40Ω/cm^2 to more than 104 Ω/cm^2 with increasing oxygen partial pressure from O to about 2%.The same tendeney of sheet resistances increasing with increasing oxygen partial pressure was observed on glass substrates.The X-ray diffraction data indicated polycrystalline filns with grain orientations predominantly along（440）and （422）directions.The intensities of （440）and （422）peaks increased slightly with the increase of oxygen partial pressure both on PC and glass substrates.The AFM images show that the ITO films on PC substrates were dense and uniform.The average grain size of the films was about 40nm.

Sub-stochiometric MoO_(x) by radio-frequency magnetron sputtering as hole-selective passivating contacts for silicon heterojunction solar cells

The silicon heterojunction(SHJ)solar cell has long been considered as one of the most promising candidates for the next-generation PV market.Transition metal oxides(TMOs)show good carrier selectivity when combined with c-Si solar cells.This has led to the rapid demonstration of the remarkable potential of TMOs(especially MoO_(x))with high work function to replace the p-type a-Si:H emitting layer.MoO_(x) can induce a strong inversion layer on the interface of n-type c-Si,which is beneficial to the extraction and conduction of holes.In this paper,the radio-frequency(RF)magnetron sputtering is used to deposit MoO_(x) films.The optical,electrical and structural properties of MoO_(x) films are measured and analyzed,with focus on the inherent compositions and work function.Then the MoO_(x) films are applied into SHJ solar cells.When the MoO_(x) works as a buffer layer between ITO/p-a-Si:H interface in the reference SHJ solar cell,a conversion efficiency of 19.1%can be obtained.When the MoOx is used as a hole transport layer(HTL),the device indicates a desirable conversion efficiency of 17.5%.To the best of our knowledge,this current efficiency is the highest one for the MoO_(x) film as HTL by RF sputtering.

Influence of O/Ar ratio on the properties of NiO thin film grown with the method of radio-frequency magnetron sputtering

In order to obtain high quality NiO thin film grown with the radio-frequency magnetron sputtering method, the influence of O/Ar ratio on the structure, band-gap, resistivity and optical transmittance of NiO thin films were studied. It was found that the obtained NiO thin film showed （111） preferred orientation and higher transparency in the visible region. With the increasing of O/ Ar ratio from 1：7 to 8： 2, the optical transmittance of NiO thin films decreased and the optical band- gap was between 3. 4 eV and 3. 7 eV, and the sheet resistivity decreased from 5. 4 ~ 107 Ω/ to 1.0 × 10^5 Ω/[]. Our study shows that the properties of NiO thin films can be adjusted in a wide range by adjusting the O/At ratio in the sputtering process.

Effects of Substrate Temperature on Properties of Transparent Conductive Ta-Doped TiO_2 Films Deposited by Radio-Frequency Magnetron Sputtering

Ta-doped titanium dioxide films are deposited on fused quartz substrates using the rf magnetron sputtering technique at different substrate temperatures. After post-annealing at 550℃ in a vacuum, all the films are crystallized into the polycrystalline anatase TiO2 structure. The effects of substrate temperature from room temperature up to 350℃ on the structure, morphology, and photoelectric properties of Ta-doped titanium dioxide films are analyzed. The average transmittance in the visible region（400-800 nm） of all films is more than 73%.The resistivity decreases firstly and then increases moderately with the increasing substrate temperature. The polycrystalline film deposited at 150℃ exhibits a lowest resistivity of 7.7 × 10^-4Ω·cm with the highest carrier density of 1.1×10^21 cm^-3 and the Hall mobility of 7.4 cm^2·V^-1s^-1.

Preparation and Characterization of Transparent Conductive Zinc Doped Tin Oxide Thin Films Prepared by Radio-frequency Magnetron Sputtering

High transparent and conductive thin films of zinc doped tin oxide （ZTO） were deposited on quartz substrates by the radio-frequency （RF） magnetron sputtering using a 12 wt% ZnO doped with 88 wt% SnO2 ceramic target.The effect of substrate temperature on the structural,electrical and optical performances of ZTO films has been studied.X-ray diffraction （XRD） results show that ZTO films possess tetragonal rutile structure with the preferred orientation of （101）.The surface morphology and roughness of the films was investigated by the atomic force microscope （AFM）.The electrical characteristic （including carrier concentration,Hall mobility and resistivity） and optical transmittance were studied by the Hall tester and UV- VIS,respectively.The highest carrier concentration of -1.144×1020 cm-3 and the Hall mobility of 7.018 cm2（V ·sec）-1 for the film with an average transmittance of about 80.0% in the visible region and the lowest resistivity of 1.116×10-2 Ω·cm were obtained when the ZTO films deposited at 250 oC.

Surface Metallization of Glass Fiber(GF)/Polyetheretherketone(PEEK) Composite with Cu Coatings Deposited by Magnetron Sputtering and Electroplating

Surface metallization of glass fiber(GF)/polyetheretherketone(PEEK)[GF/PEEK] is conducted by coating copper using electroplating and magnetron sputtering and the properties are determined by X-ray diffraction(XRD), scanning electron microscopy(SEM), and electron backscatter diffraction(EBSD).The coating bonding strength is assessed by pull-out tests and scribing in accordance with GB/T 9286-1998.The results show that the Cu coating with a thickness of 30 μm deposited on GF/PEEK by magnetron sputtering has lower roughness, finer grain size, higher crystallinity, as well as better macroscopic compressive stress,bonding strength, and electrical conductivity than the Cu coating deposited by electroplating.

Structural and magnetic properties of micropolycrystalline cobalt thin films fabricated by direct current magnetron sputtering

Pure cobalt(Co)thin films were fabricated by direct current magnetron sputtering,and the effects of sputtering power and pres-sure on the microstructure and electromagnetic properties of the films were investigated.As the sputtering power increases from 15 to 60 W,the Co thin films transition from an amorphous to a polycrystalline state,accompanied by an increase in the intercrystal pore width.Simultaneously,the resistivity decreases from 276 to 99μΩ·cm,coercivity increases from 162 to 293 Oe,and in-plane magnetic aniso-tropy disappears.As the sputtering pressure decreases from 1.6 to 0.2 Pa,grain size significantly increases,resistivity significantly de-creases,and the coercivity significantly increases(from 67 to 280 Oe),which can be attributed to the increase in defect width.Corres-pondingly,a quantitative model for the coercivity of Co thin films was formulated.The polycrystalline films sputtered under pressures of 0.2 and 0.4 Pa exhibit significant in-plane magnetic anisotropy,which is primarily attributable to increased microstress.

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.

Study of bias voltage effect on the performance of ta-C coating prepared by high power impulse magnetron sputtering

The mechanical and frictional properties of ta-C coatings deposited on the substrate surface affect applications in the field of cutting tools and wear-resistant components.In this paper,the effect of bias parameters on the performance of ta-C coatings was investigated based on high power impulse magnetron sputtering(HiPIMS)technology.The results show that bias voltage has a significant effect on the deposition rate,structure,and wear resistance of the coating.In the range of bias voltage−50 V to−200 V,the ta-C coating performance was the best under bias voltage−150 V.The thickness reached 530.4 nm,the hardness value reached 35.996 GPa,and the bonding force in-creased to 14.2 N.The maximum sp3 bond content was 59.53% at this condition.

Properties of Gallium Phosphide Thick Films Prepared on Zinc Sulfide Substrates by Radio-Frequency Magnetron Sputtering

Radio-frequency （RF） magnetron sputtering was employed to prepare gallium phosphide （GAP） thick films on zinc sulfide （ZnS） substrates by sputtering a single crystalline GaP target in an Ar atmosphere. The infrared （IR） transmission properties, structure, morphology, composition and hardness of the film were studied. Results show that both amorphous and zinc-blende crystalline phases existed in the GaP film in almost stoichiometric amounts. The GaP film exhibited good IR transmission properties, though the relatively rough surface and loose microstructure caused a small loss of IR transmission due to scattering. The GaP film also showed a much higher haraness than the ZnS substrate, thereby providing good protection to ZnS.

Effect of substrate temperature on microstructure and optical properties of single-phased Ag_2O film deposited by using radio-frequency reactive magnetron sputtering method

Using a radio-frequency reactive magnetron sputtering technique, a series of the single-phased Ag20 films are deposited in a mixture of oxygen and argon gas with a flow ratio of 2：3 by changing substrate temperature （Ts）. Effects of the Ts on the microstructure and optical properties of the films are investigated by using X-ray diffractometry, scanning electron microscopy and spectrophotometry. The single-phased Ag20 films deposited at values of Ts below 200℃ are （111） preferentially oriented, which may be due to the smallest free energy of the （111） crystalline face. The film crystallization becomes poor as the value of Ts increases from 100℃ to 225℃. In particular, the Ag20 film deposited at Ts=225℃ loses the （111） preferential orientation. Correspondingly, the film surface morphology obviously evolves from a uniform and compact surface structure to a loose and gullied surface structure. With the increase of Ts value, the transmissivity and the reflectivity of the films in the transparent region are gradually reduced, while the absorptivity gradually increases, which may be attributed to an evolution of the crystalline structure and the surface morphology of the films.

Fabrication and characterization of He-charged ODS-FeCrNi films deposited by a radio-frequency plasma magnetron sputtering technique

He-charged oxide dispersion strengthened （ODS） FeCrNi fills were prepared by a radiofrequency （RF） plasma magnetron sputtering method in a He and Ar mixed atmosphere at 150 °C.As a comparison,He-charged FeCrNi films were also fabricated at the same conditions through direct current （DC） plasma magnetron sputtering.The doping of He atoms and Y2O3 in the FeCrNi fills was realized by the high backscattered rate of He ions and Y2O3/FeCrNi composite target sputtering method,respectively.Inductive coupled plasma （ICP） and x-ray photoelectron spectroscopy （XPS） analysis confirmed the existence of Y2O3 in FeCrNi fills,and Y2O3 content hardly changed with sputtering He/Ar ratio.Cross-sectional scanning electron microscopy （SEM） shows that the FeCrNi films were composed of dense colunnarnanocrystallines and the thickness of the films was obviously dependent on He/Ar ratio.Nanoindentation measurements revealed that the FeCrNi films fabricated through DC/RF plasma magnetron sputtering methods exhibited similar hardness values at each He/Ar ratio,while the dispersion of Y2O3 apparently increased the hardness of the fills.Elastic recoil detection （ERD） showed that DC/RF magnetron sputtered FeCrNi films contained similar He amounts （～17 at.%）.Compared with the minimal change of He level with depth in DC-sputtered films,the He amount decreases gradually in depth in the RF-sputtered fills.The Y2O3-doped FeCrNi films were shown to exhibit much smaller amounts of He owing to the lower backscattering possibility of Y2O3 and the inhibition effect of nano-sized Y2O3 particles on the He element.

Epitaxial growth of ZnO on GaN/sapphire substrate by radio-frequency magnetron sputtering

Zinc oxide（ZnO） thin films were grown on n-GaN/sapphire substrates by radio-frequency（RF） magnetron sputtering.The films were grown at substrate temperatures ranging from 400 to 700℃for 1 h at a RF power of 80 W in pure Ar gas ambient.The effect of the substrate temperature on the structural and optical properties of these films was investigated by X-ray diffraction（XRD）,atomic force microscopy（AFM） and photoluminescence（PL） spectra. XRD results indicated that ZnO films exhibited wurtzite symmetry and c-axis orientation when grown epitaxially on n-GaN/sapphire.The best crystalline quality of the ZnO film is obtained at a growth temperature of 600℃.AFM results indicate that the growth mode and degree of epitaxy strongly depend on the substrate temperature.In PL measurement, the intensity of ultraviolet emission increased initially with the rise of the substrate temperature,and then decreased with the temperature.The highest UV intensity is obtained for the film grown at 600℃with best crystallization.

Effect of radio-frequency substrate bias on ion properties and sputtering behavior of 2 MHz magnetron sputtering

The effect of radio-frequency substrate bias on ion properties and sputtering behavior of 2 MHz magnetron discharge was investigated. The ion velocity distribution function(IVDF), the maximum ion energy and ion flux density were measured at the substrate by a retarding field energy analyzer. The sputtering behavior was investigated by the electric characteristics of target and bias discharges using voltage–current probe technique. It was found that the substrate bias led to the decrease of sputtering power, voltage and current with the amplitude <7.5%. The substrate bias also led to the broadening of IVDFs and the increase of ion flux density, made the energy divergent of ions impacting the substrate. This effect was further enhanced by increasing bias power and reducing discharge pressure.

Effect of gas pressure on ion energy at substrate side of Ag target radio-frequency and very-high-frequency magnetron sputtering discharge

The effect of gas pressure on ion energy distribution at the substrate side of Ag target radio-frequency(RF)and very-high-frequency(VHF)magnetron sputtering discharge was investigated.At lower pressure,the evolution of maximum ion energy(E)with discharge voltage(V)varied with the excitation frequency,due to the joint contribution of the ion generation in the bulk plasma and the ion movement across the sheath related to the ion transit sheath timeτiand RF periodτRF.At higher pressure,the evolution of E–V relationships did not vary with the excitation frequency,due to the balance between the energy lost through collisions and the energy gained by acceleration in the electric field.Therefore,for RF and VHF magnetron discharge,lower gas pressure can have a clear influence on the E–V relationship.

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.

Effects of Mg doping content and annealing temperature on the structural properties of Zn_(1-x)Mg_xO thin films prepared by radio-frequency magnetron sputtering

The doping content of Mg plays an important role in the crystalline structure and morphology properties of Zn_(1-x )Mg_xO thin films. Here,using radio-frequency magnetron sputtering method,we prepared Zn_(1-x )Mg_xO thin films on single crystalline Si(100) substrates with a series of x values. By means of X-ray diffraction(XRD) and scanning electron microscope(SEM),the crystalline structure and morphology of Zn_(1-x )Mg_xO thin films with different x values are investigated. The crystalline structure of Zn_(1-x )Mg_xO thin film is single phase with x<0.3,while there is phase separation phenomenon with x>0.3,and hexagonal and cubic structures will coexist in Zn_(1-x )Mg_xO thin films with higher x values. Especially with lower x values,a shoulder peak of 35.1° appearing in the XRD pattern indicates a double-crystalline structure of Zn_(1-x )Mg_xO thin film. The crystalline quality has been improved and the inner stress has been released,after the Zn_(1-x )Mg_xO thin films were annealed at 600 °C in vacuum condition.