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1.
Reza Keshavarzi Majid Moghadam Shahram Tangestaninejad Hamid Reza Fallah Hamed Reza Modayemzadeh 《Materials Research Bulletin》2011,46(4):615-620
In this work, the preparation of In2O3-ZnO thin films by electron beam evaporation technique on glass substrates is reported. Optical and electrical properties of these films were investigated. The effect of dopant amount and annealing temperature on the optical and electrical properties of In2O3-ZnO thin films was also studied. Different amount of ZnO was used as dopant and the films were annealed at different temperature. The results showed that the most crystalline, transparent and uniform films with lowest resistivity were obtained using 25 wt% of ZnO annealed at 500 °C. 相似文献
2.
The annealing effects on the electrical properties and microstructures of indium oxide (In2O3) thin films were investigated. The In2O3 thin films with the thickness of about 150 nm were annealed at various temperatures ranging from 100 to 600 °C in air after the sputtering deposition. It was found that the carrier density of the In2O3 thin films decreased with increasing in the annealing temperature and then started to increase at a certain temperature. This indicated that the reduction of the In2O3 thin films was promoted at high annealing temperature. The Hall mobility of the In2O3 thin films increased through the reduction; furthermore, the d-spacing of the In2O3 crystal lattice plane tended toward ideal value. It can be believed from these results that one of the principal electron scattering in the In2O3 thin films is attributed to excess oxygen atoms that expand the d-spacing. 相似文献
3.
Indium sulfide thin films prepared using spray pyrolysis, with In/S ratio 2/3 in the solution, were annealed in vacuum at 300 and 400 °C. The effect of this treatment on properties of the films was studied using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, optical absorption, transmission and electrical measurements. Optical constants of the films were calculated using the envelope method. Annealing did not affect the optical properties of the film much, but the resistivity of the films showed a drastic decrease and the grain size increased. In2S3 thin films have potential use as buffer layer in photovoltaic heterojunction devices. 相似文献
4.
The degradation of epitaxial thin films of YBa2Cu3O7 has been studied as a function of annealing temperature in air and in vacuum; some samples had an evaporated overlayer of CaF2. Degradation was monitored by the measurement of electrical properties after consecutive 30-min annealing treatments. The room-temperature resistance registered significant increases for all samples after annealing at temperatures above about 200°C; the critical current density at 77 K was degraded for annealing temperatures 400°C in air, and 200–250°C in vacuum. By annealing in oxygen at 550°C, electrical properties were restored in degraded bare YBCO samples annealed in vacuum, but not for those annealed in air. 相似文献
5.
Kaibin Ruan 《Thin solid films》2008,516(16):5248-5251
(Bi3.2La0.4Nd0.4)Ti3O12 (BLNT) thin films were prepared on Pt/Ti/SiO2/Si substrates by using chemical solution deposition technique, and the effects of annealing temperatures in the range of 550-750 °C on structure and electrical properties of the thin films were investigated. X-ray diffraction analysis shows that the thin films have a bismuth-layered perovskite structure with preferred (117) orientation. The surface morphology observation by field-emission scanning electron microscopy confirms that films are dense and smooth with uniformly distributed grains. The grain size of the thin films increases with increasing annealing temperature; meanwhile, the structural distortion of the thin films also increases. It was demonstrated that the thin films show good electrical properties. The dielectric constant and dielectric loss are 191 and 0.028, respectively, at 10 kHz for the thin film annealed at 600 °C, and the 2Pr value of the thin film annealed at 700 °C is 20.5 μC/cm2 at an electric field of 500 kV/cm. 相似文献
6.
We report on observations of structural stability of Sn-doped In2O3 (ITO) thin films during thermal annealing at low temperature. The ITO thin films were deposited by radio-frequency magnetron sputtering at room temperature. Transmission electron microscopy analysis revealed that the as-deposited ITO thin films are nanocrystalline. After thermal annealing in a He atmosphere at 250 °C for 30 min, recrystallization, coalescence, and agglomeration of grains were observed. We further found that nanovoids formed in the annealed ITO thin films. The majority of the nanovoids are distributed along the locations of the original grain boundaries. These nanovoids divide the agglomerated larger grains into small coherent domains. 相似文献
7.
Praseodymium-substituted bismuth titanate (Bi3.2Pr0.8Ti3O12, BPTO) thin films were successfully deposited on Pt(111)/Ti/SiO2/Si(100) substrates by spin coating with a sol-gel technology and rapid thermal annealing. The effects of annealing atmospheres (vacuum, ambient atmosphere and oxygen) on the growth and properties of thin films were investigated. The results show that the intensity of the (117) diffraction peak of Bi3.2Pr0.8Ti3O12 film annealed in oxygen is stronger than those annealed in ambient atmosphere and vacuum. The XRD spectra demonstrated that a highly (117) orientation could be obtained when the Bi3.2Pr0.8Ti3O12 thin film was annealed in an oxygen-sufficient environment. The BPTO thin films annealed in oxygen atmosphere exhibits the maximum remanent polarization (2Pr) of 49 μC/cm2 and a low coercive field (2Ec) of 130 kV/cm, fatigue free characteristics up to ≧ 1011 switching cycles. These results indicate that the BPTO thin film is useful in nonvolatile ferroelectric random access memory applications. 相似文献
8.
A. M. Khoviv T. A. Myachina E. G. Goncharov V. A. Logacheva E. V. Kasatkina 《Inorganic Materials》2006,42(2):108-111
The chemical interaction between indium and thin SnO and SnO2 films and between tin and thin In2O3 films during vacuum annealing was studied. The metallic films were deposited onto single-crystal silicon substrates by magnetron sputtering, the SnO and SnO2 films were produced by heat-treating the Sn film in flowing oxygen at 673 and 873 K, respectively, and the In2O3 film was produced by heat-treating the In film at 573 K. The results indicate that annealing of the In/SnO/Si and In/SnO2/Si heterostructures in vacuum (residual pressure of 0.33 × 10?2 Pa) at 773 K gives rise to the reduction of Sn and oxidation of In, whereas annealing of Sn/In2O3/Si causes partial tin substitution for indium in the cubic indium oxide lattice. 相似文献
9.
Bi1.5Zn1.0Nb1.5O7 (BZN) thin films were prepared on Pt/TiO2/SiO2/Si(100) substrates at 650 °C under an oxygen pressure of 10 Pa by using pulsed laser deposition process. The crystallinity, microstructure and electrical properties of BZN thin films were investigated to verify the influences of post-annealing thermal process on them. The X-ray diffractometer (XRD) results indicate that all Bi1.5Zn1.0Nb1.5O7 thin films without post-annealing process or with post-annealing in situ vacuum chamber and in oxygen ambient exhibit a cubic pyrochlore structure. The improved crystallinity of BZN thin films through post-annealing was confirmed by XRD and scanning electron microscope (SEM) analysis. Dielectric constant and loss tangent of the as-deposited BZN thin films are 160 and 0.002 at 10 kHz, respectively. After annealing, dielectric properties of thin films are significantly improved. Dielectric constant and loss tangent of the in situ annealed films are 181 and 0.0005 at 10 kHz, respectively. But the films post-annealed in O2 oven show the largest dielectric constant of 202 and the lowest loss tangent of 0.0002, which may attribute to the increase in grain size and the elimination of oxygen vacancies. Compared with the as-deposited BZN thin films, the post-annealed films also show the larger dielectric tunability and the lower leakage current density. 相似文献
10.
T. Siciliano M. Di GiulioM. Tepore A. GengaG. Micocci A. Tepore 《Thin solid films》2012,520(7):2455-2460
In2O3 thin films were prepared by the thermal oxidation of amorphous InSe films in air atmosphere. The structure, morphology and composition of the thermal annealed products were characterized by X-ray diffraction (XRD), scanning electron microscopy and energy-dispersive spectroscopy, respectively. The XRD patterns indicate that the as-deposited InSe films were amorphous and they fully transformed into polycrystalline In2O3 films with a cubic crystal structure in the preferential (222) orientation at a temperature around 600 °C. The optical energy gap of 3.66 eV was determined at room temperature by transmittance and reflectance measurements using UV-vis-NIR spectroscopy. A preliminary characterization shows that these films have a promising response towards NO2 gas at a working temperature around 180 °C. 相似文献
11.
Ytterbium-doped Bi4Ti3O12 (Bi3.4Yb0.6Ti3O12, BYT) ferroelectric thin films were successfully deposited on Pt(111)/Ti/SiO2/Si(100) substrates by chemical solution deposition (CSD). 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. Structure evolution and ferroelectric properties of the as-prepared thin films annealed under different temperatures (600 °C-750 °C) were studied in detail. Additionally, the mechanism concerning the dependence of electrical properties of the BYT ferroelectric thin films on the annealing temperature was discussed. 相似文献
12.
This paper describes the structural properties and electrical characteristics of thin Ho2O3 gate dielectrics deposited on silicon substrates by means of reactive sputtering. The structural and morphological features of these films after postdeposition annealing were studied by X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy. It is found that Ho2O3 dielectrics annealed at 700 °C exhibit a thinner capacitance equivalent thickness and excellent electrical properties, including the interface trap density and the hysteresis in the capacitance-voltage curves. Under constant current stress, the Weibull slope of the charge-to-breakdown of the 700 °C-annealed films is about 1.7. These results are attributed to the formation of well-crystallized Ho2O3 structure and the reduction of the interfacial SiO2 layer. 相似文献
13.
Indium tin oxide (ITO) films were deposited on glass substrates by rf magnetron sputtering using a ceramic target (In2O3-SnO2, 90-10 wt%) without extra heating. The post annealing was done in air and in vacuum, respectively. The effects of annealing on the structure, surface morphology, optical and electrical properties of the ITO films were studied. The results show that the increase of the annealing temperature improves the crystallinity of the films, increases the surface roughness, and improves the optical and electrical properties. The transmittance of the films in visible region is increased over 90% after the annealing process in air or in vacuum. The resistivity of the films deposited is about 8.125×10−4 Ω cm and falls down to 2.34×10−4 Ω cm as the annealing temperature is increased to 500°C in vacuum. Compared with the results of the ITO films annealed in air, the properties of the films annealed in vacuum is better. 相似文献
14.
Y2O3 thin film waveguides were prepared by RF magnetron sputtering. The effects of post-deposition annealing on the structure and optical properties have been investigated. The structural evolution of Y2O3 films with annealing temperature was investigated by X-ray diffraction (XRD). Spectroscopic ellipsometry was employed to determine the optical properties of Y2O3 films annealed at various temperatures. It was found that with increasing annealing temperature, the refractive index (n) of Y2O3 films increases. The optical band gap of Y2O3 films shifts to higher energy after higher temperature annealing, which is likely due to the reduction of defects and the change of crystalline structure in Y2O3 films. 相似文献
15.
Xian Ming Wu Xin Hai LiMing Fei Xu Yun He ZhangZe Qiang He Zhuo Wang 《Materials Research Bulletin》2002,37(14):2345-2353
Cathode material LiMn2O4 thin films were prepared by aqueous solution deposition using lithium acetate and manganese acetate as starting materials. The structures, morphologies, and the first discharge specific capacity of the thin films were investigated as a function of annealing temperature and time. The cycling properties of the thin films were also examined. The results show that LiMn2O4 thin films prepared by this method are homogenous and crack-free. The thin film annealed at 750°C for 30 min has good rechargeability. The capacity loss per cycle is about 0.05% after being cycled 100 times. 相似文献
16.
F.A. Al-Agel 《Vacuum》2011,85(9):892-897
The optical constants (absorption coefficient, optical band gap, refractive index, extinction coefficient, real and imaginary parts of dielectric constants) of amorphous and thermally annealed thin films of Ga15Se77In8 chalcogenide glasses with thickness 4000 Å have been investigated from absorption and reflection spectra as a function of photon energy in the wave length region 400-800 nm. Thin films of Ga15Se77In8 chalcogenide glasses were thermally annealed for 2 h at three different annealing temperatures 333 K, 348 K and 363 K, which are in between the glass transition and crystallization temperature of Ga15Se77In8 glasses. Analysis of the optical absorption data shows that the rule of non-direct transitions predominates. It was found that the optical band gap decreases with increasing annealing temperature. It has been observed that the value of absorption coefficient and extinction coefficient increases while the values of refractive index decrease with increasing annealing temperature. The decrease in optical band gap is explained on the basis of the change in nature of films, from amorphous to crystalline state. The dc conductivity of amorphous and thermally annealed thin films of Ga15Se77In8 chalcogenide glasses is also reported for the temperature range 298-393 K. It has been observed that the conduction is due to thermally assisted tunneling of the carriers in the localized states near the band edges. The dc conductivity was observed to increase with the corresponding decrease in activation energy on increasing annealing temperature in the present system. These results were analyzed in terms of the Davis-Mott model. 相似文献
17.
The interdiffusion and intermetallic compound formation of Au-Ti bilayer thin films annealed at 125 to 350 °C have been investigated. The bilayer thin films were prepared through electron beam deposition at comparatively low temperature. The interdiffusion of annealed specimens was examined by measuring electrical resistance and the depth-composition profile, and by observation using a transmission electron microscope. Interdiffusion between the thin films was detected at temperature above 175°C in a vacuum of 10–4 Pa. The starting temperature at which interdiffusion occurred decreases with lowering annealing vacuum. The intermetallic compounds AuTi, Au4Ti, Au2Ti and Ti3Au form during annealing at over 250 °C. The activation energies of Au in Ti and Ti in Au obtained by the penetration depth are approximately 0.45 and 0.41 eV, respectively. These measurements indicate that the diffusion is controlled by a short-circuit mechanism. The diffusion of Ti species in Au depends on the annealing vacuum and Au thickness. 相似文献
18.
Highly degenerate thin In2O3:Sn films were prepared by d.c. reactive sputtering of InSn alloy targets in ArO2 mixtures with a wide range of oxygen concentrations. The influence of both the oxygen concentration in the reactive mixture and the tin content of the target on the structure and electrical properties was studied. Hall measurements indicate that ionized impurities and interphase boundaries play a dominant role as causes of carrier scattering. The effectof post-deposition heat treatment in vacuum and in hydrogen was also studied. The considerable increase in the carrier concentration during reduction in hydrogen is explained in terms of the reduction mechanism. 相似文献
19.
Ruthenium dioxide thin films were reactively rf sputtered on SiO2/Si substrates and annealed in the temperature range from 150 to 500 °C. The structural and morphological properties of the films were investigated using Raman spectroscopy, transmission electron microscopy and atomic force microscopy. The increase of grain size was improved with annealing temperature. After annealing at 500 °C, the roughening of the RuO2/SiO2 interface was observed. The electrical behaviour was analysed by resistivity, thermal coefficient of resistance and low frequency noise. Good correlation between structural and electrical properties of RuO2 films was established. 相似文献
20.
The fifty seven nm thick La2O3 thin films were deposited on Si (100) substrates. After deposition, the amorphones thin films, were amorphous, were annealed at 750 and 900 °C for 1 h. It was found that their amorphous structure had been crystallized to hexagonal and cubic structures, respectively. The phase formation of the La2O3 thin films was anomalous at higher annealing temperatures. The theory of heterogeneous nucleation was used to interpret the anomalous phase formation of La2O3 films. To investigate the effects of the phase structure on these properties, Refractive indexes and dielectric constants of different structures of La2O3 films were measured. 相似文献