室温直流磁控溅射制备ITO膜及光电性能研究

室温条件下,在玻璃衬底上,采用直流磁控溅射法制备了ITO膜.研究了溅射压强,氧流量和溅射功率等工艺参数对薄膜光电性能的影响.结果表明当Ar流量为44.2 sccm和溅射时间20 min等参数不变时,溅射气压0.7 Pa,氧流量0.62 sccm和溅射功率130 W为最佳工艺条件.并得到了电阻率5.02×10-4 Ω·cm,在可见光区平均透过率80%以上ITO薄膜.     

Co,Ni-base alloy thin films deposited by r.f. magnetron sputtering in Ar/N<Subscript>2</Subscript> atmosphere

Phase composition and microstructure of CoNiCrAlY thin films deposited by r.f. Magnetron Sputtering in reactive Ar/N₂ atmosphere were determined by X-ray Diffraction. Three basic phases were observed, for increasing nitrogen partial pressure: (a) a nanocrystalline supersaturated solid solution of the alloy elements with fcc structure and interstitial nitrogen (up to 10–15%), with a sharp [111] fibre texture turning into a broad [200] component for increasing N₂ content; (b) an amorphous phase with nominal composition M₂N (with M as the alloy elements); and (c) a nanocrystalline nitride approaching the nominal composition MN. Nanocomposite coatings made of nanocrystalline fcc metal phase embedded in an amorphous matrix can be formed in a relatively narrow N₂ partial pressure range, whereas at high nitrogen content the thin films tend to form an increasing fraction of a nanocrystalline nitride in addition to the amorphous matrix.Scratch test results are different for the various systems: thin films made of (a) behave as typical plastic metals, with an increased scratch test resistance for increasing N₂ content; amorphous (b) films show a very good scratch test behaviour and tend to fail in a plastic mode, with optimal properties for systems made of fcc metal nanocrystalline/amorphous nanocomposites; thin films with a high N₂ content tend to behave in a brittle way for increasing content of the nanocrystalline nitride phase.     

磁控溅射ITO薄膜的退火处理

采用直流磁控溅射方法在室温下玻璃基板上制备ITO(Indium tin oxide)薄膜,并在真空中不同温度(100℃~400℃)下退火处理.研究了退火对薄膜表面形貌、电光特性的影响.XRD测试发现薄膜在200℃退火后结晶,优选晶向为(222).随退火温度升高,方块电阻迅速下降,表面更加平整,薄膜在可见光范围平均透过率提高到85%.     

Nanodomain and interface structure in epitaxial BaTiO<Subscript>3</Subscript> thin films on MgO deposited by magnetron sputtering

High epitaxial quality BaTiO₃ films were deposited on the MgO (001) substrate using RF magnetron sputtering at 800 °C by manipulating processing parameters. The BaTiO₃ films have a ~200 nm thickness with a very low surface roughness but a rough interface structure with respect to the substrate. The epitaxial BaTiO₃ films have a tetragonal crystal structure (a = 4.02 Å and c = 4.11 Å) with a tetragonality (c/a) of 1.02. The c-axis of the film is parallel to the growth direction as characterized by X-ray diffraction, electron diffraction, and high-resolution transmission electron microscopy. The orientation relationship between the film and the MgO is (001)_BTO//(001)_MgO and 〈100〉_BTO//〈100〉_MgO. Epitaxial nanodomains were formed in the film with a size ranging from 3 to 20 nm. The formation of the nanodomains is associated with the rough film/substrate interface due to the modification of the substrate surface characteristics (steps, terraces, and kinks) during the process. The two-dimensional interface structure between the film and the substrate was studied and its influence on the film microstructure is discussed.     

Properties of Ce-doped ITO films deposited on polymer substrate by DC magnetron sputtering

Ce-doped indium tin oxide (ITO:Ce) films were deposited on flexible polyimide substrates by DC magnetron sputtering using ITO targets containing various CeO₂ contents (CeO₂ : 0, 0.5, 3.0, 4.0, 6.0 wt.%) at room temperature and post-annealed at 200 °C. The crystallinity of the ITO films decreased with increasing Ce content, and it led to a decrease in surface roughness. In addition, a relatively small change in resistance in dynamic stress mode was obtained for ITO:Ce films even after the annealing at high temperature (200 °C). The minimum resistivity of the amorphous ITO:Ce films was 3.96 × 10^− 4 Ωcm, which was deposited using a 3.0 wt.% CeO₂ doped ITO target. The amorphous ITO:Ce films not only have comparable electrical properties to the polycrystalline films but also have a crystallization temperature > 200 °C. In addition, the amorphous ITO:Ce film showed stable mechanical properties in the bended state.     

Properties of AgInSe<Subscript>2</Subscript> films grown by magnetron sputtering

n-Type AgInSe₂ films 0.5 to 0.9 μm thick were grown by dc magnetron sputtering. As targets, we used AgInSe₂ crystals grown by a modified Bridgman process using high-purity precursors. The crystal structure, morphology, electrical conductivity, and Hall coefficient of the films were studied at various temperatures. We determined the optimal growth and annealing temperatures of the films (500 and 250°C, respectively). Using structures based on the films, we obtained the spectral dependences of their photoresponse, established the nature of interband transitions in the films, and evaluated their band gap. The ability to vary electrical and optical properties with no changes in stoichiometry is of interest for concentrated solar power applications.     

Enhanced characterization of ITO films deposited on PET by RF superimposed DC magnetron sputtering

Tin-doped indium oxide (ITO) films were deposited on polyethylene terephthalate substrates by RF superimposed DC magnetron sputtering using an ITO target composed of In₂O₃ (90 wt.%):SnO₂ (10 wt.%). The total sputtering power was maintained at 70 W and the power ratio of RF/(RF + DC) was varied from 0 to 100% in steps of 25%. The discharge voltage and deposition rate decreased with increasing RF/(RF + DC) power ratio. The ITO film deposited at a 50% RF portion of the total power showed the lowest resistivity (3.18 × 10^− 4 Ωcm), high transmittance (87.5%) and relatively good mechanical durability, which was evaluated using bending and scratch tests.     

Preparation and characterization of Mn-doped BaTiO<Subscript>3</Subscript> thin films by magnetron sputtering

Barium titanate (BaTiO₃) thin films doped with Mn (0.1–1.0 at%) were prepared by r.f. magnetron sputtering technique. Oxygen/argon (O₂/Ar) gas ratio is found to influence the sputtering rate of the films. The effects of Mn doping on the structural, microstructural and electrical properties of BaTiO₃ thin films are studied. Mn-doped thin films annealed at high temperatures (700 °C) exhibited cubic perovskite structure. Mn doping is found to reduce the crystallization temperature and inhibit the grain growth in barium titanate thin films. The dielectric constant increases with Mn content and the dielectric loss (tan δ) reveals a minimum value of 0.0054 for 0.5% Mn-doped BaTiO₃ films measured at 1 MHz. The leakage current density decreases with Mn doping and is 10⁻¹¹ A/cm⁻² at 6 kV/cm for 1% Mn-doped thin films.     

Effect of sputtering pressure and post-annealing on hydrophilicity of TiO2 thin films deposited by reactive magnetron sputtering

A series of TiO₂ thin films was deposited onto glass substrates without intentional heating or biasing by magnetron sputtering of a titanium target using Ar/O₂ reactive mixtures over a broad range of total sputtering pressures from 0.12 Pa to 2.24 Pa. Each of the film types was deposited by the threshold poisoned mode at a specific given oxygen flow rate monitored in-situ by optical emission spectroscopy. Both the sputtering pressure and thermal annealing are the key factors for the TiO₂ films to yield fast-response superhydrophilicity with a water contact angle of 5°. The mechanism of superhydrophilicity for the TiO₂ films deposited by high-pressure sputtering will be discussed based on empirical studies of X-ray diffractometry, high-resolution scanning microscopy and atomic force spectroscopy.     

Effect of target properties on transparent conducting impurity-doped ZnO thin films deposited by DC magnetron sputtering

For the purpose of using transparent conducting impurity-doped ZnO thin films in liquid crystal display (LCD) applications, the relationship between the properties of dc magnetron sputtering (dc-MS) deposited thin films and the properties of the oxide targets used to produce them is investigated. Both Al-doped and Ga-doped ZnO (AZO and GZO) thin films were deposited on glass substrates using a dc-MS apparatus with various high-density sintered AZO or GZO disk targets (diameter of about 150 mm); the target and substrate were both fixed during the depositions. Using targets with a lower resistivity results in attaining more highly stable dc-MS depositions with higher deposition rates and lower arcing. In addition, dc-MS depositions using targets with a lower resistivity produced improvements in resistivity distribution on the substrate surface. It was found that the oxygen content in deposited thin films decreased as the oxygen content of the target used in the deposition was decreased. As a result, the dc-MS deposition of transparent conducting impurity-doped ZnO thin films suitable for LCD applications requires the preparation of significantly reduced AZO and GZO targets with low oxygen content.     

Optical properties of fluoride thin films deposited by RF magnetron sputtering

Fluoride thin films for 193-nm lithography were deposited by three different types of RF magnetron sputtering. Systematic analysis of the relation between optical properties and deposition conditions of these thin films is discussed.     

磁控溅射制备ITO薄膜光电性能的研究

采用直流磁控溅射方法在玻璃基底上制备了ITO薄膜.分别用分光光度计和四探针仪测试了所制备ITO薄膜在可见光区域内的透过率和电阻率,研究了溅射气压、氧氩流量比和溅射功率三个工艺参数对ITO薄膜光电性能的影响.研究结果表明,制备ITO薄膜的最佳工艺参数为:溅射气压0.6 Pa,氧氩流量比1:40,溅射功率108 W.采用此工艺参数制备的ITO薄膜在可见光区平均透过率为81.18％,薄膜电阻率为8.9197×10-3Ω·cm.     

磁控溅射沉积制备SnSe薄膜及其热电性能研究

因为晶体结构以及热电性能各向异性,硒化锡(SnSe)沿b轴方向表现出优异的热电性能,受到业内的广泛关注.但关于SnSe薄膜研究的报道较少.本研究利用磁控溅射技术,将SnSe沉积到Si/SiO2基底得到SnSe薄膜,分析了沉积温度对SnSe薄膜结构和热电性能的影响.结果显示:沉积温度升高,晶粒尺寸相应增加,薄膜的结晶质量...     

The influence of substrate temperature on the properties of aluminum-doped zinc oxide thin films deposited by DC magnetron sputtering

Transparent, conducting, aluminum-doped zinc oxide (AZO) thin films were deposited on Corning 1737 glass by a DC magnetron sputter. The structural, electrical, and optical properties of the films, deposited using various substrate temperatures, were investigated. The AZO thin films were fabricated with an AZO ceramic target (Al₂O₃:2 wt%). The obtained films were polycrystalline with a hexagonal wurtzite structure and preferentially oriented in the (002) crystallographic direction. The lowest resistivity was 6.0 × 10⁻⁴Ω cm, with a carrier concentration of 2.7 × 10²⁰ cm⁻³ and a Hall mobility of 20.4 cm²/Vs. The average transmittance in the visible range was above 90%.     

磁控溅射制备增透ITO薄膜及其性能研究

用射频磁控溅射法在低温下制备了光电性能优良的ITO(In2O3:SnO2=1:1)薄膜。质量流量计调节氩气压强PAr为0.2～3.0Pa,氧流量fO2为0～10sccm,并详细探讨了溅射时PAr和fO2变化对ITO薄膜光学性能的影响。结果表明:fO2的改变引起薄膜中氧空位浓度变化而影响ITO薄膜折射率n;fO2对ITO靶材表面的溅射阀值和对Ar 散射而改变溅射速率。衬底表面粗糙度对ITO薄膜的折射率测量准确性有较大影响。PAr为0.8Pa,fO2为2.4sccm,薄膜厚度为241.5nm时,nmin=1.97,最大透过率为89.4%(包括玻璃基体),方阻为75.9?/□,电阻率为8.8×10-4?·cm。AFM分析表明薄膜表面针刺很少,表面平整(RMS=3.04nm)。     

ITO substrate resistivity effect on the properties of CuInSe<Subscript>2</Subscript> deposited using two-electrode system

The purpose of this work is to deposit the CuInSe₂ films on the ITO substrate by electrodeposition technique using a simplified two electrodes system and to investigate the effect of ITO sheet resistance on the fundamental properties of the resulting films. The as deposited films were annealed under argon atmosphere at 300 °C during 30 min. The structural, morphological and electrical properties were characterized respectively by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrical resistivity measurements. The optical band gap of samples was estimated using the optical absorption technique. After annealing, the XRD spectra show diffraction peaks corresponding to the single-phase chalcopyrite CuInSe₂ with (112) as main reflection. The SEM images reveal a homogeneous surface and the estimated grain size was calculated from Scherrer’s Equation with (112) peak lay in the range of 165–272 Å. The band gap, E _g, is a decreasing function with the ITO sheet resistance.     

射频磁控溅射法制备Bi_2O_3薄膜的电致变色性能研究

采用射频磁控溅射技术在ITO导电玻璃上沉积了Bi_2O_3薄膜,利用X射线衍射仪、原子力显微镜、X射线光电子谱对薄膜的微结构、表面形貌、成分和价态进行了表征。分析表明在空气气氛中350℃热处理的Bi_2O_3薄膜具有四方结构,属β-Bi_2O_3,该薄膜在-1.8-+3V的直流电压驱动下具有在透明和暗棕色之间转换的电致变色性能,着色和漂白过程中均没有其他价态(+3价以外)的Bi生成。研究发现Bi_2O_3薄膜在400-800nm的可见光波段平均透射率调制幅度可达44%,550nm处着色系数为9.6cm~2/C,该材料具有优良的电致变色性能。     

Structural and optical properties of chemically deposited Cd(S-Se): CdCl<Subscript>2</Subscript>, Sm films

Results of SEM and XRD studies, optical absorption and photoluminescence (PL) emission spectra and photoconductivity (PC), rise and decay studies are reported for Cd(S-Se): CdCl₂, Sm films prepared by chemical deposition method on glass substrates at 60°C in a water bath. SEM studies show ball-type structures along with voids which are related to layered growth. XRD studies show prominent diffraction lines of CdS and CdSe along with some peaks of CdCl₂ and impurity Sm. The values of strain (ɛ), grain size (D) and dislocation density (δ) are evaluated from XRD studies and the nature of crystallinity of the films are discussed. Optical absorption spectra also show the presence of Sm in the lattice. From the results of optical absorption spectra, the band gaps are determined. PL emission spectra of Cd(S-Se) consist of two peaks which are related to the edge emission of CdS and CdSe involving excitons. In Sm-doped emissions corresponding to transitions ⁴ G _5/2 to ⁶ H _5/2, ⁶ H _7/2 and ⁶ H _9/2 are observed. Sufficiently high photo current (I _pc) to dark current (I _dc) ratios with a maximum value of the order of 10⁶ are also obtained in some special cases. This high photosensitization is related to increase in mobility and life time of carriers due to photo excitation.     

Depth dependent properties of ITO thin films grown by pulsed DC sputtering

A systematically prepared set of ITO layers for solar cell applications has been analyzed by spectroscopic variable angle ellipsometry in order to trace the dependence of free carriers’ distribution along the film depth as a function of film thickness as well as its change upon annealing. Samples were deposited on silicon substrates with various thicknesses in steps of approximately 10–20 nm. This set was duplicated and these samples were annealed, so that for each thickness an as-deposited and an annealed sample is available. Conventionally measured electrical conductivity and morphological properties (AFM measurements) of the films have been compared with the optical constants’ inhomogeneity, i.e. material properties along the film thickness modelled by variable-angle spectroscopic ellipsometry. The obtained results show that the optical as well as electrical properties of thin ITO films prepared by pulsed DC sputtering are depth dependent. For the deposition conditions used a well-determined reproducible non-uniform distribution of free carriers within the film thickness was determined. In particular it has been found that the majority of free carriers in as-deposited ultra-thin ITO films is concentrated at sample half-depth, while their distribution becomes asymmetric for the thicker films, with a maximum located at approximately 40 nm depth. The distribution of free carriers in annealed samples is qualitatively different from that of as-deposited layers.