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1.
采用原子层沉积(ALD)方法在硅衬底上沉积了氧化铪(HfO2)薄膜,对其进行不同时间的微波退火(MWA)。采用X射线衍射(XRD)、拉曼光谱(Raman)、原子力显微镜(AFM)、紫外可见光谱(UV-Vis)、椭偏仪(SE)和阻抗分析仪对薄膜的物相结构、形貌和光电性能进行表征,研究了微波退火时间对薄膜结构、光学和电学性能的影响。结果表明:沉积态的HfO2薄膜具有非晶态性质;当微波退火时间从5 min增至20 min时,HfO2薄膜的折射率几乎不变,结晶性增强,表面粗糙度降低,但介电常数却减小。 相似文献
2.
Tantalum oxide thin films were prepared by using reactive dc magnetron sputtering in the mixed atmosphere of Ar and O2 with various flow ratios. The structure and O/Ta atom ratio of the thin films were analyzed by X-ray diffraction and X-ray photoelectron spectroscopy (XPS). The optical and dielectric properties of the Ta2O5 thin films were investigated by using ultraviolet-visible spectra, spectral ellipsometry and dielectric spectra. The results reveal that the structure of the samples changes from the amorphous phase to the β-Ta2O5 phase after annealing at 900 °C. The XPS analysis showed that the atomic ratio of O and Ta atom is a stoichiometric ratio of 2.50 for the sample deposited at Ar:O2 = 4:1. The refractive index of the thin films is 2.11 within the wavelength range 300-1000 nm. The dielectric constants and loss tangents of the Ta2O5 thin films decrease with the increase of measurement frequency. The leakage current density of the Ta2O5 thin films decreases and the breakdown strength increases with the increase of Ar:O2 flow ratios during deposition. 相似文献
3.
Yibin Li Yue Sun Wenzhu Zhang Yujie Ding Xiaodong He 《Journal of Alloys and Compounds》2008,460(1-2):115-119
Nanocrystalline aluminum embedded in amorphous dielectric alumina matrix thin films (nc-Al/α-Al2O3) was synthesized via reactive magnetron sputtering. The nc-Al/α-Al2O3 films at different oxygen partial pressures were sputtered on p-type Si substrates from a pure Al target in the mixed ambient of Ar and O2. Both deposition rate and aluminum concentration increase as the oxygen partial pressure decreases. X-ray photoelectron spectroscopy and high-resolution transmission electron microscope studies give the confirmation of nanocrystalline Al embedded in amorphous Al2O3 matrix. This nanocomposite thin film exhibits memory effect as a result of charge trapping. The flat band voltage value depends on the Al nanocrystal concentration which is related to oxygen partial pressure. 相似文献
4.
A.B. Panda K. Harish S.V. Chaure V.S. Jadhav D. Sasmal A.K. Das I. Banerjee 《Surface & coatings technology》2010,205(5):1611-1617
TiO2 thin films have been deposited at different Ar:O2 gas ratios (20:80,70:30,50:50,and 40:60 in sccm) by rf reactive magnetron sputtering at a constant power of 200 W. The formation of TiO2 was confirmed by X-ray photoelectron spectroscopy (XPS). The oxygen percentage in the films was found to increase with an increase in oxygen partial pressure during deposition. The oxygen content in the film was estimated from XPS measurement. Band gap of the films was calculated from the UV-Visible transmittance spectra. Increase in oxygen content in the films showed substantial increase in optical band gap from 2.8 eV to 3.78 eV. The Ar:O2 gas ratio was found to affect the particle size of the films determined by a transmission electron microscope (TEM). The particle size was found to be varying between 10 and 25 nm. The bactericidal efficiency of the deposited films was investigated using Escherichia coli (E. coli) cells under 1 h UV irradiation. The growth of E. coli cells was estimated through the Optical Density measurement by UV-Visible absorbance spectra. The qualitative analysis of the bactericidal efficiency of the deposited films after UV irradiation was observed through SEM. A correlation between the optical band gap, particle size and bactericidal efficiency of the TiO2 films at different argon:oxygen gas ratio has been studied. 相似文献
5.
Xiaohua ZhangWei Ren Peng ShiM. Saeed Khan Xiaofeng ChenXiaoqing Wu Xi Yao 《Journal of Alloys and Compounds》2011,509(38):9302-9306
Bi2Zn2/3Nb4/3O7 thin films were deposited on Pt/TiO2/SiO2/Si(1 0 0) substrates at a room temperature under the oxygen pressure of 1-10 Pa by pulsed laser deposition. Bi2Zn2/3Nb4/3O7 thin films were then post-annealed below 200 °C in a rapid thermal process furnace in air for 20 min. The dielectric and leakage current properties of Bi2Zn2/3Nb4/3O7 thin films are strongly influenced by the oxygen pressure during deposition and the post-annealing temperature. Bi2Zn2/3Nb4/3O7 thin films deposited under 1 Pa oxygen pressure and then post-annealed at a temperature of 150 °C show uniform surface morphologies. Dielectric constant and loss tangent are 57 and 0.005 at 10 kHz, respectively. The high resolution TEM image and the electron diffraction pattern show that nano crystallites exist in the amorphous thin film, which may be the origin of high dielectric constant in the Bi2Zn2/3Nb4/3O7 thin films deposited at low temperatures. Moreover, Bi2Zn2/3Nb4/3O7 thin film exhibits the excellent leakage current characteristics with a high breakdown strength and the leakage current density is approximately 1 × 10−7 A/cm2 at an applied bias field of 300 kV/cm. Bi2Zn2/3Nb4/3O7 thin films are potential materials for embedded capacitor applications. 相似文献
6.
Yu-Hao Zhai Yu-Juan Zhang Yi Peng Sheng-Mao Zhang Ping-Yu Zhang Xiao-Min Zhang 《稀有金属(英文版)》2016,35(2):177-183
nc-TiC/a-C:H nanocomposite films were prepared by filtered cathodic arc technique. The influence of C2H2/Ar flow ratio on the composition, structure, and mechanical properties of films was investigated by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, nanoindentation, and ball-on-disc tribometry. The films show a nanocomposite structure in which TiC crystallites are embedded in the amorphous matrix of a-C:H phase. C content in films increases with the flow ratio of C2H2/Ar, simultaneously, the crystallite size of TiC decreases. Contrary to the nc-TiC/a-C:H films deposited by magnetron sputtering in which the sp3 C content increases with C2H2 flow rate, the increase of C2H2 flow rate leads to the increase of sp2 C content in films deposited by filtered cathodic arc technique. The nc-TiC/a-C:H films deposited by cathodic arc technique have a pronounced hardness maximum of 30 GPa under the C2H2/Ar flow ratio of 12. Tribological performance of films is controlled by the sp2 content in films. Higher sp2 content promotes the formation of graphite-like transfer layer during sliding, and results in lower wear rate and friction coefficient. 相似文献
7.
Based on the optimum deposition conditions of ZrN thin film from our previous study, by varying oxygen flow rate ranging from 0 to 8 sccm, nanocrystalline ZrNxOy thin films were deposited on p-type (100) Si substrates using hollow cathode discharge ion-plating (HCD-IP) system. The objective of this study was to investigate the effect of oxygen content on the composition, structure and properties of the ZrNxOy thin films. The oxygen content of the thin film, determined using X-ray photoelectron spectroscopy (XPS), increased with increasing oxygen flow rate. As the oxygen content increased, the color of the ZrNxOy thin film changed from golden yellow to blue and then slate blue, and the microstructure observed by scanning electron microscopy (SEM) varied from columnar structure to finer grains and finally flat and featureless structure. Phase separation of ZrNxOy to ZrN and monoclinic ZrO2 was found from X-ray diffraction (XRD) patterns when the oxygen content was higher than 9.7 at.%. The hardness of the film slightly increased as the oxygen content was less than 9.7% and then decreased to 15.7 GPa, a typical hardness of ZrO2 phase, as the oxygen content further increased. The total residual stress of the film was measured using an optical method, and the residual stresses of ZrN and ZrO2 phases were determined separately using modified XRD sin2ψ method. The total stress was close to the stress in ZrN phase as the ZrO2 fraction was less than 30%, and was close to that in ZrO2 phase as the ZrO2 fraction was over 30%. The electrical resistivity of the film increased significantly with the increase of oxygen content. The film properties showed consistent trend with phase separation. As the fraction of ZrO2 phase was small, the apparent properties of the films were more close to those in ZrN. When ZrO2 fraction was over 30%, the films mainly exhibited the properties of ZrO2. 相似文献
8.
Tadahiro Aita Kazunari Ogawa Yusuke Saito Yuichi Sumiyoshi Takeshi Higuchi Shimio Sato 《Surface & coatings technology》2010,205(3):861-866
Atmospheric-pressure inductively coupled micro-plasma jet was used for deposition of SiO2 and TiOx thin films. Si and Ti alkoxides respectively were vaporized into Ar gas to be decomposed thermally in the Ar plasma jet, being deposited as the metal oxide films. Microstructures of the films were investigated as changing the plasma conditions such as Ar gas flow rate and concentration of the alkoxides in Ar gas. The SiO2 and TiOx films deposited at higher Ar gas flow rates were composed of particles of micron or submicron sizes. The SiO2 film was composed of a single layer of the particles and the particles sometimes formed unique aggregation structures. On the other hand, the TiOx film had a structure in which the particles were piled up randomly. The structures suggested that the SiO2 particles grew on the substrate whereas TiOx particles were formed in plasma gas phase. 相似文献
9.
Daniel A. Grave Zachary R. Hughes Joshua A. Robinson Thomas P. Medill Matthew J. Hollander Anna L. Stump Michael Labella Xiaojun Weng Douglas E. Wolfe 《Surface & coatings technology》2012
Thick polycrystalline gadolinium oxide (Gd2O3) films up to 11 μm in thickness were deposited via reactive electron beam-physical vapor deposition (EB-PVD) on silicon (111) substrates for use in neutron radiation detection. The effects of coating thickness, substrate temperature, and oxygen flow on film structural, electrical and optical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), capacitance–voltage (C–V) measurements, and ultraviolet–visible (UV–Vis) spectroscopy. Films were characterized as either monoclinic or mixed monoclinic and cubic phase depending on deposition parameters. Increasing the deposition temperature resulted in increased film crystallinity and cubic phase volume while decreasing the O2 flow rate resulted in increased volume of the monoclinic phase. Evidence of a thickness dependent crystallography is also presented. Electrical property measurements showed thin film dielectric constant could be tailored between 12 and 20 at 1 MHz frequency by decreasing the oxygen flow rate at deposition temperatures of 250 °C which is attributed to an increased presence of the monoclinic phase and increased film density. Band gap values were calculated from transmission measurements and ranged between 5.44 and 5.96 eV. 相似文献
10.
Twelve La2O3 doped diamond-like carbon (DLC) nanofilms were deposited using unbalanced dual-magnetron sputtering. AFM, XRD, Raman spectroscopy, AES, XPS, TEM, contact surface profiler and nanoindenter were employed to investigate the structure and tribological properties of deposited films. The results show that the La2O3 doped DLC films are amorphous. La2O3 doping obviously decreases internal stress, and effectively increases the elastic modulus. This results from the dissolving and dissolution of La2O3 within the amorphous DLC matrix. Furthermore, the friction coefficient of the doped DLC films decreases, and adhesion strength increases. These are attributed to the lubrication function of La2O3 and the formation of transition layer at interface, respectively. 相似文献
11.
SrRuO3 thin film electrodes are epitaxially grown on SrO buffered-Si(001) substrates by pulsed laser deposition. The optimum conditions of the SrO buffer layers for epitaxial SrRuO3 films are a deposition temperature of 700 °C, deposition pressure of 1 × 10?6 Torr, and thickness of 6 nm. The 100 nm thick-SrRuO3 bottom electrodes deposited above 650 °C on SrO buffered-Si (001) substrates have a rms (root mean square) roughness of approximately 5.0 Å and a resistivity of 1700 µω-cm, exhibiting an epitaxial relationship. The 100 nm thick-Pb(Zr0.2Ti0.8)O3 thin films deposited at 575 °C have a (00l) preferred orientation and exhibit 2Pr of 40 µC/cm2, Ec of 100 kV/cm, and leakage current of about 1 × 10?7 A/cm2 at 1 V. The silicon oxide phase which presents within PZT and SrRuO3 films, influences the crystallinity of the PZT films and the resistivity of the SrRuO3 electrodes. 相似文献
12.
Nanocrystalline ZrNxOy thin films were deposited on p-type Si (100) substrates using hollow cathode discharge ion-plating (HCD-IP) and the films were annealed at 700 and 900 °C in the controlled atmosphere. The purpose of this study was to investigate the phase separation, phase transformation and the accompanying change of properties of the heat-treated ZrNxOy films deposited by ion plating. With the increase of oxygen flow rate ranging from 0 to 10 sccm, the primary phase of the as-deposited films evolved from ZrN to nearly amorphous structure and further to monoclinic ZrO2 (m-ZrO2). After heat treatment at 700 and 900 °C, phase transformation occurred in the samples deposited at 8 and 10 sccm O2, where a stoichiometric crystalline Zr2ON2 was found to derive from m-ZrO2 with dissolving nitrogen (m-ZrO2(N)). The hardness of the ZrNxOy thin films could be correlated to the fraction of Zr2ON2 + m-ZrO2. The film hardness decreased significantly as the fraction of ZrO2 + Zr2ON2 exceeded ~ 60%, which was due to phase transition by increasing oxygen flow rate or phase transformation induced by heat treatment. The phase separation of m-ZrO2 from ZrN with dissolving oxygen (ZrN(O)) may relieve the residual stress of the ZrNxOy specimens deposited at 5 and 8 sccm O2, while direct formation of m-ZrO2 increased the stress of the film deposited at 10 sccm O2. On the other hand, the phase transformation from m-ZrO2(N) to Zr2ON2 by heat treatment at both 700 and 900 °C may effectively relieve the residual stress of the ZrNxOy films. 相似文献
13.
ZrNxOy thin films were deposited on AISI 304 stainless steel (304SS) substrates by reactive magnetron sputtering. The specimens were produced by sputtering a Zr target at 500 °C and the reactive gasses were N2 and O2 at various flow rates (ranging from 0 to 2 sccm). The purpose of this study was to investigate the effect of oxygen flow rate on the phase transition and accompanying mechanical properties of the ZrNxOy thin films. The oxygen contents of the thin films increased significantly with increasing oxygen flow rate. X-ray diffraction (XRD) revealed that the characteristics of the films can be divided into three zones according to the major phase with increasing oxygen content: Zone I (ZrN), Zone II (Zr2ON2) and Zone III (m-ZrO2). The hardness of the ZrNxOy films decreased with increasing oxygen content due to the formation of the soft oxide phase. Modified XRD sin2ψ method was used to respectively measure the residual stresses of ZrN, Zr2ON2 and m-ZrO2 phases. The results showed that the residual stress in ZrN was relieved as the oxygen content increased, and Zr2ON2 and m-ZrO2 were the phases with lower residual stress. Compositional depth profiles indicated that there was a ZrO2 interlayer near the film/substrates interface for all samples except the mononitride ZrN specimen. Contact angle was used as an index to assess the wettability of the film on substrate. The contact angles of ZrN, Zr2ON2 and m-ZrO2 on stainless steel were indirectly measured using Owens-Wendt method. The results showed that ZrO2 possessed the lowest wettability on 304SS among the three ZrNxOy phases, indicating that the ZrO2 interlayer may account for the spallation of the ZrNxOy films after salt spray tests. 相似文献
14.
The purpose of this study was to develop a novel low-temperature atmospheric pressure (AP) plasma system and to use the system to deposit photo-catalytic titanium dioxide (TiO2) thin film. In this study, titanium tetraisopropoxide (TTIP) was used as a precursor for TiO2 thin film deposition. The precursor was vaporized by ultrasonic oscillator and introduced into an atmospheric plasma system by argon (Ar) carrier gas. The main plasma working gas was Ar mixed with O2. Microstructure evolutions of TiO2 thin film were investigated by low-angle grazing-incidence x-ray diffraction (GID), x-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and transmission electron microscope (TEM). The photo-catalytic properties were determined by contact angle and methylene orange de-coloration testing. In this study, the substrate temperature, the precursor flow rate and the O2 flow rate were varied. TiO2 thin film grown at a temperature of 350 °C, with precursor and O2 flow rates of 20 sccm and 200 sccm, respectively, revealed the optimum photo-catalytic properties. It was also found that titanium dioxide thin films synthesized by the AP plasma method possess reasonable photo-catalytic characteristics like other deposition techniques. 相似文献
15.
Epitaxial thin films of tin ferrite (SnFe2O4) were deposited on (0 0 2) oriented strontium titanate (SrTiO3) substrate using pulsed laser deposition method. The quality and epitaxial nature of the films were investigated by X-ray diffraction technique. The phi scan of the film and the substrate shows four folds symmetry indicating cube-on-cube epitaxial growth of the film on the substrate. The optical bandgap of the film was estimated to be 2.6 eV using optical transmittance data. Magnetic measurements indicate that the coercive field and remnant magnetization of the film decrease with increase in temperature. The presence of hysteresis loop in M vs. H plot at room temperature indicates the ferromagnetic nature of the film. 相似文献
16.
In this paper, effect of annealing and O2 pressure on the structural and optical properties of pulsed laser deposited thin films of TiO2 is reported. XRD, FTIR spectra and SEM images confirm that at high annealing temperatures, the rutile phase and crystalline quality of thin films increases. Higher pressure of O2 during deposition improves the rutile phase and favors the rod like growth of TiO2 thin film. The red shift in photoluminescence (PL) spectra of TiO2 thin films with annealing temperature is reported. Contact angle measurement data for the thin films reveals the hydrophobic nature of the films. The very low reflectivity (~10%) reported in this paper may be promising for anti-reflection coating applications of pulsed laser deposited TiO2 thin films. 相似文献
17.
Hyun-Soo Kim Jae-Hong Yoon Kee-Sam Shin Katsuhisa Sugimoto 《Metals and Materials International》2002,8(2):203-209
Fe2O3-Cr2O3 artificial passive films were formed with a low pressure MOCVD technique using iron (III) acetylacetonate and chromium (III)
acetylacetonate. The relationships between the crystal structure, the chemical state of the constituent elements, and the
corrosion resistance of the films were examined in acid solutions. The films deposited above 300°C hardly dissolved in 1.0
M HCl and those deposited below 250°C, however, easily dissolved in the same solution. The dissolution rate of the films in
solution increased with decreasing substrate temperature. When polarized cathodically in 1.0 M H2SO4, the films deposited below 250°C dissolved due to the reduction of the Fe2O3 component in the films. The reduction of the Fe2O3 component was, however, suppressed on the films deposited above 300°C. Therefore, with increasing crystallinity and the amount
of M-O type chemical bonds, the corrosion resistance of the films increases in HCl and H2SO4 solutions. 相似文献
18.
Yttrium oxide (Y2O3) thin films are deposited by microwave electron cyclotron resonance (ECR) plasma assisted metal organic chemical vapour deposition (MOCVD) process at a substrate temperature of 350 °C using indigenously developed metal organic precursors (2,2,6,6-tetra methyl-3,5-heptane dionate) yttrium, commonly known as Y(thd)3 synthesized by ultrasound method. The deposited coatings are characterized by X-ray photoelectron spectroscopy, glancing angle X-ray diffraction, scanning electron microscopy, EDS and infrared spectroscopy. The characterization results indicate that it is possible to deposit non-porous coatings with excellent uniformity of a single phase cubic Y2O3 on various substrates by this process at reasonably low substrate temperature that is desirable in various manufacturing processes. 相似文献
19.
Ferroelectric properties of dysprosium-doped Bi4Ti3O12 thin films crystallized in various atmospheres 总被引:1,自引:0,他引:1
Dysprosium-doped Bi4Ti3O12 (Bi3.4Dy0.6Ti3O12, BDT) ferroelectric thin films were deposited on Pt(111)/Ti/SiO2/Si(111) substrates by chemical solution deposition (CSD) and crystallized in nitrogen, air and oxygen atmospheres, respectively. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to identify the crystal structure, the surface and cross-section morphology of the deposited ferroelectric films. The results show that the crystallization atmosphere has significant effect on determining the crystallization and ferroelectric properties of the BDT films. The film crystallized in nitrogen at a relatively low temperature of 650 ℃, exhibits excellent crystallinity and ferroelectricity with a remanent polarization of 2Pr = 24.9 ℃/cm^2 and a coercive field of 144.5 kV/cm. While the films annealed in air and oxygen at 650 ℃ do not show good crystallinity and ferroelectricity until they are annealed at 700 ℃. The structure evolution and ferroelectric properties of BDT thin films annealed under different temperatures (600-750 ℃) were also investigated. The crystallinity of the BDT films is improved and the average grain size increases when the annealing temperature increases from 600 ℃ to 750 ℃ at an interval of 50 ℃. However, the polarization of the films is not monotonous function of the annealing temperature. 相似文献
20.
Cu(In,Ga)Se2 thin films were prepared from aqueous solution by pulse electrodeposition. It was found that the co-deposition of the species occurred under a 3D growth with instantaneous nucleation. The morphology of the pulse-electrodeposited film can be improved by adjusting the duty cycle. The significant loss of indium and reduction of In-Se compound(s) accordingly were observed with decrease of duty cycle. Chalcopyrite structure Cu(In,Ga)Se2 films with p-type behavior and enhancement in crystallinity were obtained after annealing treatment in Ar atmosphere. 相似文献