Properties of dc magnetron sputtered Cu2O films prepared at different sputtering pressures

The sputtering pressures maintained during the deposition of Cu₂O films, by dc reactive magnetron sputtering, influence the structural, electrical and optical properties. The crystalline orientation mainly depends on the sputtering pressure. The films deposited at a sputtering pressure of 4 Pa showed single-phase Cu₂O films along (1 1 1) direction. The electrical resistivity of the films increased from 1.1 × 10¹ Ω cm to 3.2 × 10³ Ω cm. The transmittance of the films increased from 69% to 88% with the increase of sputtering pressure from 2.5 Pa to 8 Pa.     

射频磁控溅射制备氧化钒薄膜的研究

氧化钒（VOx）薄膜是一种广泛应用于红外热成像探测的薄膜材料,研究VOx薄膜的制备工艺、获取高电阻温度系数（TCR）的VOx薄膜具有重要意义。以高纯金属钒作靶材,采用射频磁控溅射的方法在室温下制备了VOx薄膜。主要研究了氩氧流量比以及功率等工艺参数对薄膜TCR的影响,获得了较好的工艺参数。采用万用表和X射线光电子能谱仪（XPS）分别测试了不同条件下射频磁控溅射法制备的VOx薄膜的电阻特性和薄膜成分,测试结果表明,采用所获得的较好工艺参数制备的VOx薄膜TCR值大于1.8%。     

Characterization of ZnO thin films grown on various substrates by RF magnetron sputtering

In this study we investigated properties of ZnO thin films deposited on both oxygen-containing substrates and a substrate without oxygen content at various O₂/Ar reactant gas ratios. Deposition of ZnO on indium-tin oxide (ITO) resulted in the best crystallinity, whereas the least degree of crystallization was observed from ZnO deposited on glass. All the films were found to have compressive stress, which was relieved by annealing in O₂ environment. ZnO films deposited on glass revealed p-type conductivity when prepared at O₂/Ar ratio of 0.25 whereas those on SiN_x yielded p-type conductivity when prepared at O₂/Ar ratio of 4. In addition, shallower oxygen interstitial seemed to be found from films with better crystallinity. The largest shift in binding energy of Zn_2p3/2 was observed from ZnO prepared on glass at O₂/Ar ratio of 0.25, whereas that of O_1s was obtained from ZnO deposited on SiN_x at O₂/Ar ratio of 4. A model was proposed in terms of O₂ diffusion and hydrogen desorption in order to account for the observed property variations depending on substrates and O₂/Ar ratios.     

Dependence of substrate temperature of Zn0.8Co0.2O films deposited by pulsed DC magnetron sputtering

We have investigated the microstructure, electrical and magnetic properties of the ZnCoO thin films, which were prepared by the asymmetrical bipolar-pulsed DC magnetron sputtering as a function of substrate temperature. The structural properties of ZnCoO films were characterized with a high resolution XRD. The XRD patterns of the ZnCoO films showed a strong (0 0 2) preferential orientation. The average crystallite size was 23–35 nm, which was estimated from full width at half maximum of XRD results. The electrical resistivity of the films were measured by the van der Pauw method through Hall measurement and showed below 10⁻¹ Ω cm above 300 °C. The magnetic properties of the ZnCoO films were analyzed by the alternating gradient magnetometer at room temperature. All of the films were exhibited the ferromagnetic nature. The high conductivity and room temperature ferromagnetism of the ZnCoO films above 300 °C suggested that the possibility for the application to diluted magnetic semiconductors.     

Influence of substrate bias voltage on the properties of magnetron sputtered Cu2O films

Thin films of cuprous oxide (Cu₂O) were deposited on glass substrates at various bias voltages using DC reactive magnetron sputtering technique. The effects of substrate bias voltage on structural, electrical and optical properties were systematically analyzed. The crystallographic structure and orientation of the crystallites were strongly influenced by the bias voltage.     

Characteristics of ZnO:In thin films prepared by RF magnetron sputtering

In-doped ZnO (ZnO:In) transparent conductive thin films were deposited on glass substrates by RF magnetron sputtering. The effect of substrate temperature on the structural, electrical and optical properties of the ZnO:In thin films was investigated. It was found that higher temperature improves the crystallinity of the films and promotes In substitution easily. ZnO:In thin films with the best crystal quality were fabricated at 300 °C, which exhibit a larger grain size of 29 nm and small tensile strain of 0.9%. The transmittance of all the films was revealed to be over 85% in the visible range independence of the substrate temperatures and the lowest resistivity of ZnO:In thin films is 2.4×10⁻³ Ω cm.     

Effects of annealing temperature and method on structural and optical properties of TiO2 films prepared by RF magnetron sputtering at room temperature

TiO₂ thin film was deposited on non-heated Si(1 0 0) substrate by RF magnetron sputtering. The as-deposited films were annealed by a conventional thermal annealing (CTA) and rapid thermal annealing (RTA) at 700 and 800 °C, and the effects of annealing temperature and method on optical properties of studied films were investigated by measuring the optical band gaps and FT-IR spectra. And we also compared the XRD patterns of the studied samples. The as-deposited film showed a mixed structure of anatase and brookite. Only rutile structures were found in samples annealed above 800 °C by CTA, while there are no special peaks except the weak brookite B(2 3 2) peak for the sample annealed at (or above) 800 °C by RTA. FT-IR spectra show the broad peaks due to Ti-O vibration mode in the range of 590-620 cm⁻¹ for the as-deposited film as well as samples annealed by both annealing methods at 700 °C. The studied samples all had the peaks from Si-O vibration mode, which seemed to be due to the reaction between TiO₂ and Si substrate, and the intensities of these peaks increased with increasing of annealing temperature. The optical band gap of the as-deposited film was 3.29 eV but it varied from 3.39 to 3.43 eV as the annealing temperature increased from 700 to 800 °C in the samples annealed by CTA. However, it varied from 3.38 to 3.32 eV as the annealing temperature increased from 700 to 800 °C by RTA.     

Violet and blue-green luminescence from Ti-doped ZnO films deposited by RF reactive magnetron sputtering

Pure and Ti-doped zinc oxide (TZO) films are deposited using radio frequency (RF) reactive magnetron sputtering at different RF powers. Micro-structural and optical properties in doped ZnO films are systematically investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electronic microscopy (SEM), and a fluorescence spectrophotometer. The results indicate that ZnO films show stronger preferred orientation toward the c$c$-axis and smoother surface roughness after Ti doping. As for TZO films, the full width at half maxima (FWHM) of (002) diffraction peaks decreased first and then increased, reaching a minimum of about 0.92° at 150 W, while the residual compressive stress of the TZO film prepared at 150 W became the largest. The photoluminescent (PL) spectra measured at room temperature reveal a violet, a blue and two green emissions. Intense violet and blue-green luminescence is obtained for the sample deposited at higher RF power. The origin of these emissions is discussed.     

Effect of RF power and sputtering pressure on the structural and optical properties of TiO2 thin films prepared by RF magnetron sputtering

TiO₂ thin films were deposited onto quartz substrates by RF magnetron sputtering. The samples deposited at various RF powers and sputtering pressures and post annealed at 873 K, were characterized using X-ray diffraction (XRD), micro Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), UV-vis spectroscopy and photoluminescence (PL) spectroscopy. XRD spectrum indicates that the films are amorphous-like in nature. But micro-Raman analysis shows the presence of anatase phase in all the samples. At low sputtering pressure, increase in RF power favors the formation of rutile phase. Presence of oxygen defects, which can contribute to PL emission is evident in the XPS studies. Surface morphology is much affected by changes in sputtering pressure which is evident in the SEM images. A decrease in optical band gap from 3.65 to 3.58 eV is observed with increase in RF power whereas increase in sputtering pressure results in an increase in optical band gap from 3.58 to 3.75 eV. The blue shift of absorption edge in all the samples compared to that of solid anatase is attributed to quantum size effect. The very low value of extinction coefficient in the range 0.0544-0.1049 indicates the excellent optical quality of the samples. PL spectra of the films showed emissions in the UV and visible regions.     

Structural and electrical properties of fluorine-doped zinc tin oxide thin films prepared by radio-frequency magnetron sputtering

Transparent and conductive thin films of fluorine doped zinc tin oxide (FZTO) were deposited on glass substrates by radio-frequency (RF) magnetron sputtering using a 30 wt% ZnO with 70 wt% SnO₂ ceramic targets. The F-doping was carried out by introducing a mixed gas of pure Ar, CF₄, and O₂ forming gas into the sputtering chamber while sputtering ZTO target. The effect of annealing temperature on the structural, electrical and optical performances of FZTO thin films has been studied. FZTO thin film annealed at 600 °C shows the decrease in resistivity 5.47 × 10⁻³ Ω cm, carrier concentration ∼10¹⁹ cm⁻³, mobility ∼20 cm² V⁻¹ s⁻¹ and an increase in optical band gap from 3.41 to 3.60 eV with increasing the annealing temperatures which is well explained by Burstein–Moss effect. The optical transmittance of FZTO films was higher than 80% in all specimens. Work function (ϕ) of the FZTO films increase from 3.80 eV to 4.10 eV through annealing and are largely dependent on the amounts of incorporated F. FZTO is a possible potential transparent conducting oxide (TCO) alternative for application in optoelectronics.     

射频磁控溅射法制备ZnS多晶薄膜及其性质

实验采用射频磁控溅射法在玻璃衬底上沉积了ZnS多晶薄膜,研究了沉积气压、退火温度和衬底温度对ZnS薄膜质量的影响.利用X射线衍射(XRD)分析了薄膜的微结构,并计算了内应力值.通过紫外-可见光分光光度计测量了薄膜的透过谱,计算了Urbach能量和禁带宽度.利用扫描电子显微镜(SEM)观察了薄膜的表面形貌.结果表明: 衬底温度为室温时沉积的ZnS薄膜具有较大的压应力,并且内应力值随着工作气压增大而增大,在300 ℃下进行退火处理后内应力松弛,衬底温度为350 ℃时制备的ZnS薄膜内应力小,透过率高,经300 ℃退火处理后结晶质量有所提高. 关键词： ZnS薄膜 射频磁控溅射 内应力     

Fabrication of Cu2O nanocrystalline thin films photosensor prepared by RF sputtering technique

Cuprous oxide (Cu₂O) nanocrystalline thin films were prepared on two types of substrates known as crystalline silicon and amorphous glass, by radio frequency reactive magnetron sputtering method. Scanning electron microscopy images confirmed that Cu₂O particles covered the entire surface of both substrates with smoothing distribution. The root mean square surface roughness for the prepared Cu₂O thin films on glass and Si (111) substrates is 4.16, and 3.36 nm, respectively. Meanwhile, X-ray diffraction results demonstrated that the two phases of Cu₂O and CuO were produced on Si (111) and glass substrates. The optical bandgap of Cu₂O thin films synthesised on glass substrate is 2.42 eV. Furthermore, the prepared Cu₂O nanocrystalline thin films have showed low reflectance value in the visible spectrum. Metal-Semiconductor-Metal photodetector based Cu₂O nanocrystalline thin films deposited onto Si (111) was fabricated using aluminium and platinum, with the current-voltage and photoresponse characteristic investigated under various applied bias voltages. The fabricated Metal-Semiconductor-Metal (M-S-M) photodetector had shown 126% sensitivity in the presence of 10 mW/cm² of 490 nm light with 1.0 V bias, displaying 90 and 100 ms response and recovery times, respectively. These findings have demonstrated the suitability of M-S-M Cu₂O photodetector as an affordable photosensor in the future.     

Fabrication of p-ZnO:ZrN thin films by RF magnetron sputtering

An attempt has been made to fabricate p-ZnO thin films from the ZrN mixed ZnO targets by RF magnetron sputtering. The targets of different ZrN concentrations (0, 1, 2, and 4?mol%) have been prepared by solid-state reaction route. The ZrN-codoped ZnO films grown on semi-insulating Si (100) substrates have been characterized by X-ray diffraction (XRD), photoluminescence (PL), Hall effect measurement, time-of-flight secondary ion mass spectrometer (ToF-SIMS), and atomic force microscopy (AFM). XRD studies reveal that all films are oriented along (002) plane. The Hall measurements showed p-conductivity for 1 and 2?mol% ZrN-codoped ZnO films. Further, it has been found that 1?mol% ZrN-codoped film has low resistivity (7.5?×?10^?2?Ω?cm) and considerable hole concentration (8.2?×?10¹⁸?cm^?3) by optimum incorporation of nitrogen due to best codoping. The red shift in near-band-edge emission observed from PL well acknowledged the p-conduction in 1 and 2?mol% ZrN-codoped ZnO film. The incorporation of N and Zr atoms in the ZnO matrix has been confirmed by ToF-SIMS analysis. The increase in peak to valley roughness (R _pv) with increase of doping concentration has been observed from AFM analysis. ZnO homojunction has also been fabricated with the best codoped p-ZnO film and it showed typical rectification behavior of a diode. The junction parameters have also been determined for the fabricated homojunction.     

Study of nanocrystalline VO2 thin films prepared by magnetron sputtering and post-oxidation

Nanocrystalline VO2 thin films were deposited onto glass slides by direct current magnetron sputtering and postoxidation. These films undergo semiconductor-metal transition at 70°C, accompanied by a resistance drop of two magnitude orders. The crystal structures and surface morphologies of the VO2 films were characterized by x-ray diffraction (XRD) and atomic force microscope (AFM), respectively. Results reveal that the average grain size of VO2 nanograins measured by XRD is smaller than those measured by AFM. In addition, Raman characterization indicates that stoichiometric VO2 and oxygen-rich VO2 phases coexist in the films, which is supported by x-ray photoelectron spectroscopy (XPS) results. Finally, the optical properties of the VO2 films in UV-visible range were also evaluated. The optical band gap corresponding to 2p-3d inter-band transition was deduced according to the transmission and reflection spectra. And the deduced value, E opt2p-3d = 1.81 eV, is in good agreement with that previously obtained by theoretical calculation.     

磁控溅射制备W掺杂VO2/FTO复合薄膜及其性能分析

为了获得相变温度低且热致变色性能优越的光学材料, 室温下在F:SnO₂ (FTO)导电玻璃基板表面沉积钨钒金属膜, 再经空气气氛下的热氧化处理, 制备了W掺杂VO₂/FTO复合薄膜, 利用X射线光电子能谱、X射线衍射和扫描电镜对薄膜的结构和表面形貌进行了分析. 结果表明: 高温热氧化处理过程中没有生成W, F, V混合氧化物, W以替换V原子的方式掺杂. 与采用相同工艺和条件制备的纯VO₂/FTO复合薄膜相比, W掺杂VO₂薄膜没有改变晶面取向, 仍具有(110)晶面择优取向, 相变温度下降到35 ℃左右, 热滞回线收窄到4 ℃, 高低温下的近红外光透过率变化量提高到28%. 薄膜的结晶程度明显提高, 表面变得平滑致密, 具有很好的一致性, 对光电薄膜器件的设计开发和工业化生产具有重要意义. 关键词： W掺杂 2')" href="#">VO₂ FTO导电玻璃 磁控溅射     

单靶溅射制备铜锌锡硫薄膜及原位退火研究

采用衬底加热溅射铜锌锡硫(CZTS)四元化合物单靶制备CZTS薄膜,并研究原位退火对制备薄膜的影响.结果表明:在溅射结束后快速升温并保持一段时间,所得到的样品相比于未原位退火的CZTS薄膜结晶质量更好,且表面更平整致密;原位退火后的CZTS薄膜太阳电池性能参数也相应地有所提升,其开路电压(V_(OC))为575 mV,短路电流密度(J_(SC))为8.32 mA/cm~2,光电转换效率达到1.82%.     

磁控溅射法制备β型Fe3Si8M系三元薄膜

二元β-FeSi2是-种非常有潜力的环境友好型半导体，但由于是线性化合物，所以很难制备较高质量的β单相．本文从β-FeSi2相的基本团簇出发，利用“团簇＋连接原子”结构模型，设计制备了Fe3SisM（M=B，Cr，Ni，Co）系三元薄膜．研究了Fe3Si8M系三元薄膜的结构、成分和光电特性．结果表明，溅射态薄膜都为非晶态，经850℃／4h退火后可全部转换为晶态，引入的第三组元M不同会影响退火后的相转变和结晶质量，Cr和B为第三组元时可实现单-β相，Co作为第三组元时，薄膜以Ⅸ相为主表现为金属特性．B，Cr和Ni作为第三组元的样品中半导体性质都有不同程度的体现，但相比较而言，Fe2．7Si8480．9薄膜的半导体性能最为明显，其电阻率为0．17Ω．cm、载流子浓度为2．8×10^20cm^-3、迁移率为0．13cm2／V．S，带隙宽度约为0．65eV．所以引入合适的第三组元可以扩展序相相区，并实现晶态三元β型硅化物薄膜与二元β-FeSi2薄膜的半导体性能相近．     

The effects of substrate temperatures on the electrical properties of CaZrO3 thin films prepared by RF magnetron sputtering

The radio frequency magnetron sputtering technology (RFMS) was employed to deposit perovskite structure orthogonal phase CaZrO₃ thin films on Pt/Ti/SiO₂/Si substrates. The effects of substrate temperatures on structure and electrical properties of these films were investigated in detail. The CaZrO₃ thin films were systematically characterized by means of X-ray diffraction (XRD), Scanning electron microscope (SEM), Multi-frequency LCR meter (HP4294A) and Radiant Precision Workstation to study the phase structure, cross-section morphology, dielectric and ferroelectric properties at different substrate temperatures. The result indicates that these films can withstand 80 V DC Bias voltage and have excellent stability of frequency, voltage and temperature. The CaZrO₃ thin film prepared at 550 °C turned out to be mainly orthorhombic CaZrO₃ phase with high permittivity, low dielectric loss, extremely low leakage current (at 1 MHz, the dielectric constant is 39.42, the dielectric loss is 0.00455, the quality factor is 220 and the leakage current density is 9.11 × 10⁻⁷A/cm² at 80 V applied voltage.). This work demonstrates that higher substrate temperature can boost the formation of orthorhombic CaZrO₃ phase and the CaZrO₃ thin film prepared by RF magnetron sputtering is a very promising paraelectric material in the application of thin film capacitor.     

外加磁场对射频磁控溅射制备铝掺杂氧化锌薄膜影响的研究

利用射频磁控溅射法制备了铝掺杂氧化锌(AZO)透明导电薄膜,在传统的磁控溅射系统中引入外加磁场,研究了外加磁场对AZO薄膜沉积速率、形貌结构及光电特性的影响.研究结果表明,外加磁场后薄膜的沉积速率从不加磁场的13.04 nm/min提高到了19.93 nm/min;外加磁场后薄膜表面平整致密、颗粒大小均匀,结晶质量较高,而不加磁场薄膜表面形貌呈蠕虫状,薄膜质量较差.溅射时间为90 min时,外加磁场前后AZO薄膜方阻分别为30.74?/和12.88?/.外加磁场对薄膜可见光透过率影响不大,但使薄膜的吸收边蓝移现象更明显.运用ansys软件对磁控溅射二维磁场分布模拟后发现,外加磁场提高了靶上方横向磁场强度,改善了磁场分布的均匀性,加强了磁场对电子的磁控作用,提高了靶电流,是AZO薄膜的溅射速率、光电性能和形貌结构得到提高和优化的原因.     

The properties of transparent conducting molybdenum-doped ZnO films grown by radio frequency magnetron sputtering

Transparent conducting molybdenum-doped zinc oxide films are prepared by radio frequency(RF) magnetron sputtering at ambient temperature.The MoO3 content in the target varies from 0 to 5 wt%,and each film is polycrystalline with a hexagonal structure and a preferred orientation along the c axis.The resistivity first decreases and then increases with the increase in MoO3 content.The lowest resistivity achieved is 9.2 × 10-4.cm,with a high Hall mobility of 30 cm2.V-1.s-1 and a carrier concentration of 2.3×1020 cm-3 at an MoO3 content of 2 wt%.The average transmittance in the visible range is reduced from 91% to 80% with the increase in the MoO3 content in the target.