铁电薄膜存储器底电极Pt/Ti的制备及性能研究

应用射频磁控溅射方法 ,在Si基片上采用不同的溅射工艺制备了铁电薄膜底电极Pt/Ti,并分析了在不同温度下退火后材料的电导率性能和粘结力性能 ,从理论和实验上分析了不同的溅射工艺和退火处理对底电极性能的影响。     

Fabrication and Ultraviolet Absorption of Sol–Gel-Derived Germanium Oxide Glass Thin Films

Germanium oxide glass thin films were prepared by the sol–gel method and annealed under reduced atmosphere to create more oxygen-deficient defects. The densification and crystallization were examined depending on sintering and annealing conditions. Thus, homogeneous germanium oxide thin films with a high content of oxygen vacancies were fabricated. Ultraviolet absorption and oxygen vacancies of the films were investigated as a function of annealing temperature and time. Optical absorption in the 5-eV region due to the formation of oxygen vacancies is enhanced with increasing annealing temperature and time. The formation energy of oxygen vacancies is calculated to be about 1.0 eV.     

Recrystallization of Oxygen Ion Implanted Ba0.7Sr0.3TiO3 Thin Films

The crystallization behavior of chemical-solution-deposited and amorphous Ba_0.7Sr_0.3TiO₃ (BST) thin films was analyzed with respect to the evolution of the structural and dielectric properties of the films as a function of the annealing temperature. The amorphous films were produced by oxygen ion implantation into crystalline BST thin films. In the amorphous thin films, the crystallization to the perovskite phase occurred at T = 550°C, whereas the as-deposited CSD films showed the first crystalline XRD-reflex only after annealing at T = 650°C. Here a carbon-rich intermediate phase delayed the crystallization process to higher temperatures.     

Effect of annealing on SiC thin films prepared by pulsed laser deposition

Crystalline cubic SiC thin films were successfully fabricated on Si(100) substrates by using laser deposition combined with a vacuum annealing process. The effect of annealing conditions on the structure of the thin films was investigated by X-ray diffraction and Fourier transform infrared spectroscopy. It was demonstrated that amorphous SiC films deposited at 800°C could be transformed into crystalline phase after being annealed in a vacuum and that the annealing temperature played an important role in this transformation, with an optimum annealing temperature of 980°C. Results of X-ray photoelectron spectroscopy revealed the approximate stoichiometry of the SiC films. The characteristic microstructure displayed in a scanning electron microscope image of the films was indicative of epitaxial growth along the (100) plane.     

Study of Cu-based Al-doped ZnO multilayer thin films with different annealing conditions

AZO/Cu/AZO multilayer thin films produced under different annealing conditions are studied in this paper, to examine the effects of atmosphere and annealing temperature on their optical and electrical properties. The multilayer thin films are prepared by simultaneous RF magnetron sputtering (for AZO) and DC magnetron sputtering (for Cu). The thin films were annealed in a vacuum or an atmosphere of oxygen at temperatures ranging from 100 to 400 °C in steps of 100 °C for 3 min. High-quality multilayer films (at Cu layer thickness of 15 nm) with resistivity of 1.99×10⁻⁵ Ω-cm and maximum optical transmittance of 76.23% were obtained at 400 °C annealing temperature in a vacuum. These results show the films to be good candidates for use as high quality electrodes in various displays applications.     

Enhanced conductance properties of UV laser/RTA annealed Al-doped ZnO thin films

Thin films comprising 0.5 mol% aluminum-doped zinc oxide (AZO) were prepared on glass substrates by a spin-coating method for transparent conducting oxide (TCO) applications. UV laser was selected for the annealing of AZO thin films, due to the well matched energy bandgap between UV laser and AZO films. After the rapid thermal annealing (RTA) process, post UV laser annealing was carried out by varying the scan speed of the laser beam, and the effects of laser annealing on the structural, morphological, electrical, and optical properties were analyzed. The results indicated that UV laser annealing based on various scan speeds affects the microstructure, sheet resistance, and optical transmittance of the AZO thin films, compared with those of the only RTA processed thin films. X-ray diffraction (XRD) analysis showed that all films that preferentially grew normally on the substrate had a (002) peak. The optical transmittance spectra of the laser/RTA annealed AZO thin films exhibited greater than 83% transmittance in the visible region. Also, the sheet resistance (1.61 kΩ/sq) indicated that optimized UV laser annealing after the RTA process improves film conductance.     

Improved photoluminescence emission and gas sensor properties of ZnO thin films

In this article, we report a comparative study of the influence of pressure-assisted (1.72 MPa) versus ambient pressure thermal annealing on both ZnO thin films treated at 330 °C for 32 h. The effects of pressure on the structural, morphological, optical, and gas sensor properties of these thin films were investigated. The results show that partial preferential orientation of the wurtzite-structure ZnO thin films in the [002] or [101] planes is induced based on the thermal annealing conditions used (i.e., pressure assisted or ambient pressure). UV–vis absorption measurements revealed a negligible variation in the optical -band gap values for the both ZnO thin films. Consequently, it is deduced that the ZnO thin films exhibit different distortions of the tetrahedral [ZnO₄] clusters, corresponding to different concentrations of deep and shallow level defects in both samples. This difference induced a variation of the interface/bulk-surface, which might be responsible for the enhanced optical and gas sensor properties of the pressure-assisted thermally annealed film. Additionally, pressure-assisted thermal annealing of the ZnO films improved the H₂ sensitivity by a factor of two.     

溶胶-凝胶法制备钛酸锶钡铁电薄膜的研究

钛酸锶钡(BST)薄膜是一类重要的铁电薄膜材料。采用溶胶-凝胶法制备了不同组分的具有钙钛矿结构的BST薄膜。利用X射线衍射技术(XRD),研究了不同退火条件下BST薄膜的结晶特性,结果表明制备的BST薄膜形成了单一的钙钛矿结构;利用扫描电子显微镜(SEM)和原子力显微镜(AFM)观察了薄膜的表面形貌,结果表明制备的BST薄膜光滑,平整,无明显的孔洞和裂纹,且生长良好。BST薄膜的晶粒细致,排列整齐,分布均匀,呈现球状。     

Orientation mechanism during crystallization of apatite-type lanthanum silicate thin films from an amorphous precursor

Control of the crystallization and orientation of apatite-type lanthanum silicate (LSO) plays an important role in designing and improving the LSO synthesis process. The mechanisms that determine the c-axis preferential orientation of LSO thin films synthesized by chemical solution deposition and their correlation with preparation conditions were investigated. Crystallization was found to be initiated preferentially at the surface of the precursor thin films. It was also found that the orientation of LSO thin films was largely governed by the orientations of the LSO nuclei that formed at the surface of the precursor thin films. In addition, the c-axis orientation was influenced by the atmosphere used during crystallization and the Si/La ratio in the precursor thin films. An oxygen atmosphere during annealing and lower Si/La ratios reduced the degree of c-axis orientation.     

SrBi_2Ta_2O_9薄膜的制备和铁电性能研究

用一种新的低温过程制备了SrBi2Ta2O9铁电薄膜。在Sol-Gel方法中用Pt/Ti/SiO2/Si作衬底,研究了薄膜的结构和电特性。SrBi2Ta2O9薄膜在淀积Pt上电极之前和之后都要退火,第一次退火在760乇氧压下600℃时退火30分钟,在第二次退火后薄膜结晶良好。     

退火工艺对Pb(Zr_(0.55)Ti_(0.45))O_3铁电薄膜结晶取向的影响

用射频磁控溅射法在Pt(111)/Ti/SiO2/Si上成功的制备了Pb(zr0.55Ti0.45)O3(PZT)铁电薄膜,通过传统退火(CFA)和快速退火(RTA)不同的退火方式,获得了(100)和(111)择优取向的铁电薄膜。对薄膜电学特性的测试表明,薄膜的织构对其电学性能有很大影响,(111)取向的薄膜与(100)取向的薄膜相比,剩余极化Pr和矫顽场Ec较大,但抗疲劳特性却较差。     

Electrodeposition of iron–palladium thin films

FePd thin films were electrodeposited from ammonium citrate complex baths. The effects of various electrodeposition and post heat treatment conditions including pH, current density, bath concentrations, substrates and annealing temperature on composition, material, and magnetic properties were systematically investigated. In these baths, the deposited iron content increased linearly with an increase in current density from 1 to 5 mA cm⁻² producing films with compositions extending from Fe₇Pd₉₃ to Fe₉₁Pd₉. Magnetic saturation (M_S) of electrodeposited FePd thin films linearly increased with increase in deposited iron content (i.e. 1.8 T for Fe₈₂Pd₁₈ and 0.1 T for Fe₁₉Pd₈₁) which is similar to its bulk counterparts. The effects of post-heat treatment on the phase and crystal structure of near equiatomic FePd electrodeposits (i.e. Fe₄₈Pd₅₂) was investigated by subjecting electrodeposits to different annealing temperatures from 400 to 600 °C under reducing environment. L1₀ FePd phase was formed from nanocrystalline FePd solid solution and the crystallinity improved with increasing annealing temperatures.     

The preparation and properties of PZT thin film by sputering method

The ferroelectric PZT thin films were prepared on Pt/Ti/SiO₂/Si substrate by RF sputtering method followed by the rapid thermal annealing. The preparation of the Pt and Ti thin films as bottom electrode, and their influences on the PZT thin films were studied in details. The substrate temperature during sputtering was room temperature; the rapid thermal annealing temperature was 500°C-750°C and the annealing time was 30-70s. The influences of different preparation parameters on the structure and electric properties were studied with X-ray diffraction technique and RT66A Standardized Ferroelectric Test System. The electric properties of the prepared PZT thin film was: P_a=39μc/cm₂, P_r = 9.3 μc/cm², E_c=28KV/mm, ε=300, p=10⁹ω⋅cm.     

Structural and Optical Properties of Sol–Gel-Derived Au/BaTiO3 Nanocomposite Thin Films

Au/BaTiO₃ nanocomposite thin films with different Au concentrations were prepared by a sol–gel process. The films were characterized using X-ray diffraction, thermal analyses, X-ray absorption spectroscopy, UV-vis spectroscopy, and transmission electron microscopy. The effects of Au concentration and annealing temperature on the structural and optical properties of composite films were investigated. Gold doping lowered the crystallization temperature of as-synthesized amorphous BaTiO₃ and enhanced its crystallinity in post-deposition annealing. The Au–BaTiO₃ interface was also investigated and no alloying occurred between Au and BaTiO₃. The evolution of Au surface plasmon resonance spectra with increasing annealing temperature was observed in the 10 mol% Au/BaTiO₃ thin films. The variations of band-gap energy for Au/BaTiO₃ films were also discussed.     

Wide Color Variation in SiNO Thin Films Dispersed with Precipitated TiN Nano Particles

Amorphous thin films of Ti_1?ySi_y(N,O) with y ≥ 0.38 were prepared by reactive sputter deposition in a nitrogen atmosphere. Thermal annealing of the films in an ammonia flow above 800°C yielded Si(N,O) amorphous thin films dispersed with precipitated TiN nanosized particles. The film color changed with Si content y and the annealing conditions, from carrot orange to cream yellow in the as‐deposited films due to their oxynitride nature, and from dark green to canary yellow and from iron blue to horizon blue at respective annealing temperatures of 800°C and 900°C due to metallic nature of the TiN nanosized particles precipitated in the annealing.     

离子束增强沉积制备p-ZnO薄膜

采用离子束增强沉积技术制备了ZnO薄膜,分析了退火温度、退火气氛对所制备ZnO薄膜的结构、电学特性和发光特性的影响。利用IBED法获得的薄膜p型N-In共掺ZnO薄膜在氮气下退火,随着退火温度的升高,薄膜电阻值先降低后升高,然后再降低。而在氧气下退火,即使退火温度只有400℃,薄膜的电阻很快变大。     

Influence of annealing atmosphere on the structure, resistivity and transmittance of InZnO thin films

Dependence of the electrical and optical properties of In₂O₃–10 wt% ZnO (IZO) thin films deposited on glass substrates by RF magnetron sputtering on the annealing atmosphere was investigated. The electrical resistivities of indium zinc oxide (IZO) thin films deposited on glass substrate can be effectively decreased by annealing in an N₂ + 10% H₂ atmosphere. Higher temperature (200 °C) annealing is more effective in decreasing the electrical resistivity than lower temperature (100 °C) annealing. The lowest resistivity of 6.2 × 10⁻⁴ Ω cm was obtained by annealing at 200 °C in an N₂ + 10% H₂ atmosphere. In contrast, the resistivity was increased by annealing in an oxygen atmosphere. The transmittance of IZO films is improved by annealing regardless of the annealing temperature.     

Surface Oxidation of Ge33As12Se55 Films

Ge₃₃As₁₂Se₃₃ films deposited by ultrafast pulse laser deposition were annealed at various temperatures and pressures, and the dependence of the surface oxidation on the processing conditions was investigated by X-ray photoelectron spectroscopy (XPS). We found that even as-grown film contains a thin oxidized surface and the oxygen distribution exponentially decays along the normal direction of the films regardless of different processing conditions. The critical thicknesses of the oxidized layers were 6.5, 11, 48, and 98 nm, respectively, for the as-grown, 250°C annealing sample for 4 h under 1 × 10⁻⁶ Torr, and 150° and 250°C annealing samples for 15 h under 20 mTorr.     

Preparation of Bi-Sr-Ca-Cu-O Thin Films by Sputtering under a Variable Magnetic Field

Bi-Sr-Ca-Cu-O thin films were deposited on MgO(100) substrates by a new sputtering method which controls the film composition with magnetic fields over the target. Films having compositions close to Bi₂Sr₂Ca₂Cu₃O_x were annealed at 880°C to show superconductivity at moderately high T_c's. Auger electron spectroscopy indicated a chemical interaction between the film and the substrate during the annealing, and this information was utilized to improve the annealing conditions.     

Titanium Diffusion into (K0.5Na0.5)NbO3 Thin Films Deposited on Pt/Ti/SiO2/Si Substrates and Corresponding Effects

Lead-free (K_0.5Na_0.5)NbO₃ (KNN) thin films were prepared on Pt/Ti/SiO₂/Si substrates by a sol–gel processing method, and titanium diffusion from the substrates into the KNN films under different thermal treatment conditions were investigated by the secondary ion mass spectroscopy depth profile and X-ray photoelectron spectroscopy surface analysis. Titanium diffusion was evident in all the KNN thin films, which was further aggravated not only by increasing the annealing temperature, but also surprisingly by higher ramping rate attributed to the resulting larger grain boundaries. The pronounced effects of the titanium diffusion and the resulting substitution of Ti⁴⁺ for Nb⁵⁺ with different valence states on the composition, structure, and electrical properties of the KNN thin films are analyzed and discussed. The results showed that the Ti diffusion from the substrate played a crucial role in affecting the structure and electrical properties of the ferroelectric KNN thin films deposited on Pt/Ti/SiO₂/Si substrate.