共查询到20条相似文献,搜索用时 15 毫秒
1.
M. Kodu J. Raud T. Avarmaa J.-S. Choi R. Jaaniso M.-S. Lee Y.T. Matulevich V. Sammelselg 《Thin solid films》2010,519(2):846-851
In this work, pulsed laser-deposited thin films of MgO were studied for application in plasma display panels. The firing voltage (FV) of discharge cells with MgO films was measured and the film structure was investigated as a function of film deposition conditions. MgO thin films were deposited at oxygen pressure and substrate temperature between 0.02-5 Pa and 260-600 °C, respectively. The structure of thin films was investigated by using X-ray diffraction, X-ray reflection and atomic force microscopy methods. It was found that the FV is strongly correlated with the film deposition conditions and structural properties. In general, the FV values were smaller for the films with higher crystallinity and density. The crystallinity and the density of the films increased when the deposition temperature was raised and the O2 pressure was reduced. The lowest FV values (~ 120 V) were obtained at the growth temperature of 550 °C and at O2 pressures below 1 Pa. 相似文献
2.
CaCu3Ti4O12 (CCTO) thin films were successfully deposited on Pt/Ti/SiO2/Si(1 0 0) substrates using pulsed-laser deposition technique. The crystalline structure and the surface morphology of the CCTO thin films were greatly affected by the substrate temperature and oxygen pressure. Thin films with a (2 2 0) preferential orientation were obtained at the substrate temperature above 700 °C and oxygen pressure above 13.3 Pa. The 480-nm thin films deposited under 720 °C and 26.6 Pa have a fairly high dielectric constant of near 2000 at 10 kHz and room temperature. The values of the dielectric constant and loss and their temperature-dependence under different frequency are comparable with those obtained in the epitaxial CCTO films grown on oxide substrates. 相似文献
3.
The influence of oxygen pressure on the structural and electrical properties of vanadium oxide thin films deposited on glass substrates by pulsed laser deposition, via a 5-nm thick ZnO buffer, was investigated. For the purposes of comparison, VO2 thin films were also deposited on c-cut sapphire and glass substrates. During laser ablation of the V metal target, the oxygen pressure was varied between 1.33 and 6.67 Pa at 500 °C, and the interaction and reaction of the VO2 and the ZnO buffer were studied. X-ray diffraction studies showed that the VO2 thin film deposited on a c-axis oriented ZnO buffer layer under 1.33 Pa oxygen had (020) preferential orientation. However, VO2 thin films deposited under 5.33 and 6.67 Pa were randomly oriented and showed (011) peaks. Crystalline orientation controlled VO2 thin films were prepared without such expensive single crystal substrates as c-cut sapphire. The metal-insulator transition properties of the VO2/ZnO/glass samples were investigated in terms of electrical conductivity and infrared reflectance with varying temperatures, and the surface composition was investigated by X-ray photoelectron spectroscopy. 相似文献
4.
《Materials Letters》2005,59(24-25):2994-2997
Highly c-axis oriented LiNbO3 thin films have been deposited on Si (111) substrates by pulsed laser deposition. A stoichiometric sintered LiNbO3 is used as the target. The c-axis orientation and stoichiometry of LiNbO3 films are strongly influenced by substrate temperature and oxygen pressure. The substrate temperature 600 °C and oxygen pressure 20–30 Pa are found to be optimized parameters for the growth of textured film. The results showed that the size and the density of droplets decreased with increasing substrate temperature, and droplets would disappear when substrate temperature is increased above 600 °C. The surface microstructures of LiNbO3 films under optimized conditions are fine, uniform and dense. The AFM images ensured that the as-grown films are good enough to be integrated with the semiconductor devices. 相似文献
5.
The microwave dielectric properties of Ba0.6Sr0.4TiO3 1 mol% W-doped thin films deposited using pulsed laser deposition, are improved by a novel oxygen deposition profile. The thin films were deposited onto (001) MgO substrates at a temperature of 720 °C. A comparison is made between three different oxygen ambient growth conditions. These include growth at a single oxygen pressure (6.7 Pa) and growth at two oxygen pressures, one low (6.7 Pa) and one high (46.7 Pa). Films were deposited in a sequence that includes both a low to high and a high to low transition in the oxygen deposition pressure. Following deposition, all films were post-annealed in 1 atm of oxygen at 1000 °C for 6 h. The dielectric Q (defined as 1 / tanδ) and the dielectric constant, εr, were measured at room temperature, at 2 GHz, using gap capacitors fabricated on top of the dielectric films. The percent dielectric tuning (defined as (εr(0 V) − εr(40 V)) / εr(0 V) × 100) and figure of merit (FOM) (defined as percent dielectric tuning × Q(0 V)) were calculated. The film deposited using the two-stage growth conditions, 6.7 / 46.7 Pa oxygen, showed a maximum Q(0 V) value with high percent dielectric tuning and gave rise to a microwave FOM twice as large as the single stage growth condition. The improved dielectric properties are due to initial formation of a film with reduced interfacial strain, due to the formation of defects at the film/ substrate interface resulting in a high Q(0 V) value, followed by the reduction of oxygen vacancies which increases the dielectric constant and tuning. 相似文献
6.
M.G. TsoutsouvaC.N. Panagopoulos D. PapadimitriouI. Fasaki M. Kompitsas 《Materials Science and Engineering: B》2011,176(6):480-483
Zinc oxide (ZnO) thin films were deposited on soda lime glass substrates by pulsed laser deposition (PLD) in an oxygen-reactive atmosphere. The structural, optical, and electrical properties of the as-prepared thin films were studied in dependence of substrate temperature and oxygen pressure. High quality polycrystalline ZnO films with hexagonal wurtzite structure were deposited at substrate temperatures of 100 and 300 °C. The RMS roughness of the deposited oxide films was found to be in the range 2-9 nm and was only slightly dependent on substrate temperature and oxygen pressure. Electrical measurements indicated a decrease of film resistivity with the increase of substrate temperature and the decrease of oxygen pressure. The ZnO films exhibited high transmittance of 90% and their energy band gap and thickness were in the range 3.26-3.30 eV and 256-627 nm, respectively. 相似文献
7.
Good quality transparent conducting Al-doped ZnO films were deposited on quartz substrates from a high purity target using pulsed electron deposition (PED). Two series of films were made, one deposited at room temperature but at four pressures, viz., 0.7, 1.3, 2.0 and 2.7 Pa of oxygen and one deposited at 1.3 Pa oxygen pressure but at the substrate temperature ranged from room temperature to 600 °C. In order to evaluate the effect of substrate temperature and oxygen pressure on the properties of obtained films, various characterization techniques were employed including X-ray diffraction, stylus profiler, scanning electron microscope, optical spectrophotometer and electrical resistivity. For the first series films, the optimal oxygen pressure of 1.3 Pa was found to bring about the appropriate energetic deposition atoms which results in the best crystallinity. For the second series films, the lowest resistivity was obtained in the film grown at 400 °C. An attempt was made to reduce the resistivity by lowering the oxygen pressure to 0.5 Pa which was the lower limit of working pressure of the PED system. The obtained results indicate that PED is a suitable technique for growing transparent conducting ZnO films. 相似文献
8.
Tin oxide thin films were deposited by pulsed laser ablation at different oxygen partial pressures and substrate temperatures. Information on the structural and morphological properties of the deposited thin films has been obtained by means of X-ray photoelectron, Fourier transform infrared absorption spectroscopies and scanning electron microscopy. The expansion of the laser generated plasma has been studied by means of time resolved fast photography. Different expansion regimes were observed: in vacuum the plasma follows a free expansion one while the raise of the background oxygen pressure leads to the development of a shock wave. It was found that only at 13.3 Pa of oxygen gas, in the presence of a shock wave, the deposition of stoichiometric films, at relatively low substrates temperature, is attainable. The correlation between the observed dynamics of the plasma expansion and the structural properties of the deposited films is presented and discussed. 相似文献
9.
ZnO thin films on Si(111) substrate were deposited by laser ablation of Zn target in oxygen reactive atmosphere; Nd-YAG laser
with wavelength of 1064 nm was used as laser source. The experiments were performed at laser energy density of 31 J/cm2, substrate temperature of 400 °C and various oxygen pressures (5–65 Pa). X-ray diffraction was applied to characterize the
structure of the deposited ZnO films and the optical properties of the ZnO thin films were characterized by photoluminescence
with an Ar ion laser as a light source using an excitation wavelength of 325 nm. The influence of the oxygen pressure on the
structural and optical properties of ZnO thin films was investigated. It was found that ZnO film with random growth grains
can be obtained under the condition of oxygen pressure 5–65 Pa. It will be clearly shown that the grain size and the formation
of intrinsic defects depend on the oxygen partial pressure and that high optical quality of the ZnO films is obtained under
low oxygen pressure (5 Pa, 11 Pa) conditions. 相似文献
10.
等离子体辅助反应式脉冲激光熔蚀制备AlN薄膜的低温生长 总被引:1,自引:0,他引:1
使用等离子体辅助反应式脉冲激光溅射沉积薄膜的方法在Si(111)和Si(100)基片上已经成功地低温制备出AlN多晶膜。实验表明,当脉冲能量密度DE=1.0J·cm-2,脉冲频率f=5Hz,氮气气压PN2=1.33×104Pa,基底温度tsub=200℃,放电电压V=650V,基靶距离dS-T=4cm时薄膜的生长速度等于6nm/min。AlN薄膜的折射率为2.05,和基底的取向关系分别为:AlN(110)∥Si(111)和AlN(100)∥Si(100)。 相似文献
11.
Nanostructured tin oxide thin films were deposited on the Si (100) substrate using the pulsed laser deposition technique at different substrate temperatures (300, 450 and 600 °C) in an oxygen atmosphere. The structure and morphology of the as-deposited films indicate that the film crystallinity and surface topography are influenced by the deposition temperature by changing from an almost amorphous to crystalline microstructure and smoother topography at a higher substrate temperature. The photoluminescence measurement of the SnO2 films shows three stable emission peaks centered at respective wavelengths of 591, 554 and 560 nm with increasing deposition temperature, contributed by the oxygen vacancies. 相似文献
12.
La0.5Sr0.5CoO3−δ (LSCO) thin films were deposited on yttria stabilized zirconia (YSZ) substrates by pulsed laser deposition (PLD) for application to thin film solid oxide fuel cell electrodes. During the deposition, the substrate temperature was varied from 450 to 750°C, and the oxygen pressure in the chamber was varied from 80 to 310 mTorr. Films deposited at 650°C and an oxygen background pressure of 150 mTorr were mostly (100) oriented. Deposition at higher temperatures or under lower oxygen pressures lead to mostly (110) oriented films. Films with low electrical resistivity of 10−3 Ω·cm were obtained. 相似文献
13.
Property variations of direct-current reactive magnetron sputtered copper oxide thin films deposited at different oxygen partial pressures 总被引:1,自引:0,他引:1
Cuprous oxide (Cu2O) and cupric oxide (CuO) thin films were deposited on glass substrates at different oxygen partial pressures by direct-current reactive magnetron sputtering of pure copper target in a mixture of argon and oxygen gases. Oxygen partial pressure was found to be a crucial parameter in controlling the phases and, thus, the physical properties of the deposited copper oxide thin films. Single-phase Cu2O thin films with cubic structure were obtained at low oxygen partial pressure between 0.147 Pa and 0.200 Pa while higher oxygen partial pressure promoted the formation of CuO thin films with base-centered monoclinic structure. Polycrystalline Cu2O thin films deposited with oxygen partial pressure at 0.147 Pa possessed the lowest p-type resistivity of 1.76 Ω cm as well as an optical band gap of 2.01 eV. On the other hand, polycrystalline CuO thin films deposited with oxygen partial pressure at 0.320 Pa were also single phase but showed a n-type resistivity of 0.19 Ω cm along with an optical band gap of 1.58 eV. 相似文献
14.
Nanocrystalline iron oxide thin films have been deposited on various substrates such as quartz, MgO(100), and Si(100) by pulsed laser deposition technique using excimer KrF laser (248 nm). The orientations, crystallite size and lattice parameters were studied using X-ray diffraction. The XRD results show that the films deposited on MgO and Si substrates are highly oriented and show only (400) and (311) reflections respectively. On the other hand, the orientation of the films deposited on quarts substrate changed from (311) to (400) with an increase in the substrate temperature from 400 degrees C to 600 degrees C, indicating thereby that the film growth direction is highly affected with nature of substrate and substrate temperature. The surface morphology of the deposited films was studied using Atomic Force Microscopy (AFM) and spherical ball like regular features of nanometer size grains were obtained. The magnetic properties were studied by Superconducting Quantum Interference Device (SQUID) magnetometer in the magnetic field +/- 6 Tesla. The magnetic field dependent magnetization (M-H) curves of all the Fe3O4 thin films measured at 5 K and 300 K show the ferrimagnetic nature. The electrochemical sensing of dopamine studied for these films shows that the film deposited on MgO substrate can be used as a sensing electrode. 相似文献
15.
We have studied the dependence of dielectric properties on the deposition temperature of BiFeO3 thin films grown by the pulsed laser deposition technique. Thin films have been grown onto amorphous silica glass substrates with pre-patterned Au in-plane capacitor structures. It is shown that on the amorphous glass substrate, BiFeO3 films with a near-bulk permittivity of 26 and coercive field of 80 kV/cm may be grown at a deposition temperature of about 600 °C and 1 Pa oxygen pressure. Low permittivity and higher coercive field of the films grown at the temperatures below and above 600 °C are associated with an increased amount of secondary phases. It is also shown that the deposition of BiFeO3 at low temperature (i.e. 500 °C) and post deposition ex-situ annealing at elevated temperature (700 °C) increases the permittivity of a film. The applied bias and time dependence of capacitance of the films deposited at 700 °C and ex-situ annealed films are explained by the de-pinning of the ferroelectric domain-walls. 相似文献
16.
Koichi Mizuno Hideaki Adachi Kentaro Setsune 《Journal of Low Temperature Physics》1996,105(5-6):1571-1576
Superconducting thin films of HgBa2CuO4 have been grown in situ by using a sputtering method for the first time. (100) SrTiO3 was used as substrates and heated between 500 ° C to 600 ° C during the film deposition. By setting the deposition conditions properly, c axis oriented HgBa2CuO4 films were grown perpendicularly to the substrate surface. It was found that Hg composition in the deposited films had close relation to the sputtering gas, namely, the oxygen partial pressure, Hg could remain in the film when the partial pressure of oxygen was lower than in the case of the other oxide superconductors such as Bi cuprates. The optimum oxygen partial pressure for the crystallized thin film ranged from 0.1 Pa to 0.01 Pa with total gas pressure of 0.6 Pa. The superconducting transition was observed at around 75K. 相似文献
17.
18.
《Thin solid films》1987,151(3):355-364
Indium oxide films 25–550 Å thick were reactively evaporated at an oxygen pressure of about 0.27 Pa and at a substrate temperature between room temperature and 400°C. The dependence of the structure of the films on the substrate temperature and on the film thickness was studied using transmission electron microscopy and electron diffraction. It was found that thick films (about 550 Å) were amorphous at room temperature, partially crystallized at 50–125°C and crystalline at 150–400°C. The crystallinity of the films deposited at 150–250°C also depended markedly on the film thickness. Very thin films about 25 Å thick were quasi-amorphous, but with increasing film thickness the amorphous phase transformed into a crystalline phase.The thermal transformation of the amorphous films after deposition was also studied. Amorphous films about 550 Å thick deposited at room temperature and 100°C crystallized at 230°C and 210°C respectively. 相似文献
19.
The heteroepitaxial growth dynamics of STO thin films on (100) LaAlO3 substrate by pulsed laser deposition has been studied. The laser energy density was found to be an important factor to determine
the growth mechanics. High laser energy density is benefit to two dimensional layer-by-layer growth. Island growth prevails
at low substrate temperature. STO thin films deposited at low oxygen partial pressure showed pellicular square grains. High
oxygen partial pressure resulted in spherical STO grains. Step-terrace on substrate surface acts as a preferential nucleation
site for adatoms, which leads to step-flow growth. STO thin films with atomic flat surface has been prepared on step-terraced
substrate. 相似文献
20.
Superconducting thin films of Bi(Pb)-Sr-Ca-CuO system were prepared by depositing the film onto silver substrate by d.c. electrodeposition
technique with dimethyl sulphoxide bath in order to examine the effect of Pb addition to the BSCCO system. The films were
deposited at the potential of -0.8 V vs saturated calomel electrode (SCE) onto the silver substrate. The different preparative
parameters such as deposition potential, deposition time were studied and optimized. These films were then oxidized electro-chemically
at room temperature in an alkaline (1 N KOH) solution, and also at 600°C temperature in an oxygen atmosphere. The films showed
the superconducting behaviour, with Tc values ranging between 85 K and 96 K, respectively. 相似文献