N掺杂Cu2O薄膜的低温沉积及快速热退火研究

采用氧化亚铜(Cu_2O)陶瓷靶,利用射频磁控溅射沉积法在氮气和氩气的混合气氛下制备了N掺杂Cu_2O(Cu_2O∶N)薄膜,并在N_2气氛下对薄膜进行了快速热退火处理,研究了N_2流量和退火温度对Cu_2O∶N薄膜的生长行为、物相结构、表面形貌及光电性能的影响。结果显示,在衬底温度300℃、N_2流量12sccm条件下生长的薄膜为纯相Cu_2O薄膜;在N_2气氛下对预沉积薄膜进行快速热退火处理不影响薄膜的物相结构,薄膜的结晶质量随退火温度(450℃)的升高而显著改善;快速热退火处理能改善薄膜的结晶质量和缺陷,降低光生载流子的散射,增强载流子的传输,预沉积Cu_2O∶N薄膜经400℃退火处理后展示出较好的电性能,薄膜的霍尔迁移率(μ)为27.8cm~2·V~(-1)·s~(-1)、电阻率(ρ)为2.47×10~3Ω·cm。研究表明低温溅射沉积和快速热退火处理能有效改善Cu_2O∶N薄膜的光电性能。     

X-ray and Magnetoresistance Measurements of Electrodeposited Cu-Co Granular Films

Granular CoxCu1-x alloy films were prepared by electrodeposition at room temperature directly onto semiconducting Si substrate. X-ray diffraction (XRD) revealed that the as-deposited films formed single phase metastable fcc alloy structure. The fcc lattice parameter αwas found to decrease linearly with increasing Co concentration x in the studied range. The giant magnetoresistance (GMR) of the films was improved after annealing. Pure Co fcc diffraction peaks were observed in the diffractogram of the annealed sample, indicating phase separation occurred upon annealing. The optimal annealing temperature was 450℃. The maximum of magnetoresistance (MR) ratio 8.21% was obtained for the Co20Cu80 thin film after annealing at 450℃for 1 h. The saturation field decreased upon annealing in the MR curves of Co20Cu80 film.     

Synthesis of TaZnO thin films using combinatorial magnetron sputtering and its electrical, structural and optical properties

The structural, electrical, and optical properties of tantalium zinc oxide (TaZnO) thin films grown using combinatorial magnetron sputtering system were investigated. To explore the effects of film thickness and post annealing treatment on the properties of the films, we have fabricated TaZnO sample libraries having different thicknesses and carried out post annealing treatment. Sample libraries fabricated at room temperature showed the resistivity ranged 2.1 to approximately 7.1 x 10(-3) Omega cm, while the films post annealed at 200 degrees C under 1 mTorr exhibited the resistivity as low as 1.2 x 10(-3) Omega cm. XRD measurements revealed that the film structure was strongly depended on the film thickness, showing that the structure was changed from amorphous to polycrystalline with increasing the film thickness. Furthermore, it was found that figure of merit (0TC), which was determined by T% and Rs of the TaZnO films, showed maximum value as the films with a thickness of 230 nm was post-annealed at 200 degrees C under vacuum of 1 mTorr.     

Contribution study of properties of copper indium diselenide thin films

Stoichiometric powder of CuInSe₂ (CIS) was prepared from molten stoichiometric quantities of the elements. The structure analyzed by X-ray diffraction powder (XRD), shows mainly the chalcopyrite phase. CIS polycrystalline thin films deposited from this powder have been grown on glass substrates in vacuum by thermal evaporation method. The structural and electrical properties of both as-deposited and annealed films were studied using X-ray diffraction and dark conductivity measurements respectively. As-prepared films at room temperature showed an amorphous structure. However, the chalcopyrite structure with (112) preferential orientation was observed after annealing in vacuum at 400 °C during 30 min. The influence of the annealing process on the dark conductivity of the films was also discussed.     

Effect of annealing temperature on the properties of IZO films and IZO based transparent TFTs

This work shows the effect of the annealing temperature and atmosphere on the properties of r.f. magnetron sputtered indium-zinc oxide (IZO) thin-films of two types: one a conductive film (as-deposited, room temperature) that exhibits a resistivity of 3.5 × 10^− 4 Ω cm; the other, a semiconductor film with a resistivity ∼ 10² Ω cm. The annealing temperatures were changed between 125 and 500 °C. Crystallization of the more conductive films was already noticeable at temperatures around 400 °C. Three different annealing atmospheres were used — vacuum, air and oxygen. For the conductive films, only the oxygen atmosphere was critical, leading to an increase of the electrical resistivity of more than one order of magnitude, for temperatures of 250 °C and above. Concerning the semiconductor films, both temperature and atmosphere had a strong effect on the film's properties, and the resistivity of the annealed films was always considerably smaller than the as-deposited films. Finally, some results of the application of these films to transparent TFTs are shown.     

Coexistence of ultraviolet photo-response and room-temperature ferromagnetism in polycrystalline ZnO thin films

The coexistence of ultraviolet (UV) photoconductivity (PC) and room-temperature ferromagnetism (RTFM) is observed in polycrystalline ZnO thin films deposited by unbalanced magnetron sputtering under high oxygen pressure. A significant increase in PC (∼ 870% to 40 000%) is observed with increasing film thickness and the consequent structural disorder and film porosity. In contrast, the saturation magnetization (M_S) at room temperature is found to decrease from 1.02 emu/g to 0.53 emu/g with increasing film thickness from 50 to 150 nm.     

Electrical and optical properties of annealed gallium arsenide thin films on glass substrates

The effects of annealing in vacuum on the electrical and optical properties of GaAs thin films deposited by the flash evaporation method were studied. Thin films of compound GaAs deposited upon glass substrates at room temperature were annealed in a vacuum of 2×10^–6 torr at different temperatures up to 350° C. The properties of the films depended strongly on annealing temperature. The lowest resistivity measured was about 1.6 × 10⁴ cm at an annealing temperature of about 240° C. The activation energy of as-deposited and annealed films were measured and compared. Optical absorption measurements of the asdeposited samples and the samples annealed at a temperature of 240° C were made as a function of photon energy.     

退火条件对Sn掺杂ZnO薄膜光电性能的影响

采用溶胶-凝胶法在普通载玻片上制备Sn掺杂ZnO薄膜(SZO薄膜)。研究空气退火、低真空退火、高真空退火、氮气退火、三高退火、循环退火6种不同退火条件对SZO薄膜光电性能的影响。结果表明:6种不同的退火条件制备的SZO薄膜均为纤锌矿结构且具有c轴择优取向生长的特性。高真空退火下,SZO薄膜的结晶状况和电学性质最优,最低电阻率可达到5.4×10~(-2)Ω·cm。薄膜的可见光区平均透过率均大于85%。薄膜在390nm和440nm附近(325nm光激发下)都出现光致发光峰,在空气、氮气、低真空中退火后薄膜440nm处发光强度最为显著。     

Influence of the annealing in nitrogen atmosphere on the XRD, EDX, SEM and electrical properties of chemical bath deposited CdSe thin films

The influence of annealing in nitrogen atmosphere on the structure, optical and electrical properties of cadmium selenide (CdSe) thin films deposited by chemical bath deposition (CBD) onto glass substrates was studied. The samples were annealed in nitrogen atmosphere at various temperatures. A transition from metastable nanocrystalline cubic to stable polycrystalline hexagonal phase has been observed after annealing. The as-deposited CdSe thin films grow in the nanocrystalline cubic phase with optical band gap 1.93 eV. The electrical resistivity of the thin films has been measured in order of 10⁶ Ω cm. The activation energy of the samples has been found to be 0.26–0.19 eV at low temperature region, and 0.36–0.56 eV at high temperature region. It was also found that the activation energy and the resistivity of the films decrease with the increasing annealing temperature.     

Structural, electrical and optical studies of SILAR deposited cadmium oxide thin films: Annealing effect

Successive ionic layer adsorption and reaction (SILAR) method has been successfully employed for the deposition of cadmium oxide (CdO) thin films. The films were annealed at 623 K for 2 h in an air and changes in the structural, electrical and optical properties were studied. From the X-ray diffraction patterns, it was found that after annealing, H₂O vapors from as-deposited Cd(O₂)_0.88(OH)_0.24 were removed and pure cubic cadmium oxide was obtained. The as-deposited film consists of nanocrystalline grains of average diameter about 20-30 nm with uniform coverage of the substrate surface, whereas for the annealed film randomly oriented morphology with slight increase in the crystallite size has been observed. The electrical resistivity showed the semiconducting nature with room temperature electrical resistivity decreased from 10⁻² to 10⁻³ Ω cm after annealing. The decrease in the band gap energy from 3.3 to 2.7 eV was observed after the annealing.     

The effect of rapid thermal annealing on structural and electrical properties of TiB2 thin films

This work reports on the effect of post-deposition rapid thermal annealing on the structural and electrical properties of deposited TiB₂ thin films. The TiB₂ thin films, thicknesses from 9 to 450 nm, were deposited by e-beam evaporation on high resistivity and thermally oxidized silicon wafers. The resistivity of as-deposited films varied from 1820 μΩ cm for the thinnest film to 267 μΩ cm for thicknesses greater than 100 nm. In the thickness range from 100 to 450 nm, the resistivity of TiB₂ films has a constant value of 267 μΩ cm.

A rapid thermal annealing (RTA) technique has been used to reduce the resistivity of deposited films. During vacuum annealing at 7 × 10⁻³ Pa, the film resistivity decreases from 267 μΩ cm at 200 °C to 16 μΩ cm at 1200 °C. Heating cycles during RTA were a sequence of 10 s. According to scanning tunneling microscopy analysis, the decrease in resistivity may be attributed to a grain growth through polycrystalline recrystallization, as well as to an increase in film density.

The grain size and mean surface roughness of annealed films increase with annealing temperature. At the same time, the conductivity of the annealed samples increases linearly with grain size. The obtained results show that RTA technique has a great potential for low resistivity TiB₂ formation.     

Surface morphological, structural, electrical and optical properties of annealed vanadyl tetra tert-butyl 2, 3 naphthalocyanine thin films

Vanadyl Tetra Tert-Butyl 2, 3 Naphthalocyanine (VTTBNc) thin films have been grown at room temperature by physical vapor deposition technique. The article describes the role of air and vacuum annealing on VTTBNc thin film surface morphology, structure, electrical conductivity and optical absorbance on the basis of respective measurements like atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray Diffractogram (XRD), DC electrical conductivity with integrated electrodes and UV-visible absorption spectra.     

AlSb多晶薄膜材料的性能研究

采用共蒸法制备了新型AlSb多晶薄膜. 通过XRF、XRD、Hall测试及电导率温度关系等研究了AlSb多晶薄膜的组分、结构及性能. 分析表明,刚沉积的AlSb薄膜为非晶相,在540℃以上退火转变为AlSb相,转变的程度取决于退火的温度及Al、Sb的原子配比,其中N_Al∶N_Sb为47.2∶52.8,580℃退火后的薄膜多晶转变最为明显,结晶度较高;测试结果表明,退火后的AlSb薄膜为p型间接带隙半导体,载流子浓度为10¹⁹cm^-1,吸收系数为10⁴,而且在升降温阶段电导率发生不可逆变化. 这种薄膜用于TCO/CdS/AlSb结构的太阳电池器件中已经得到200mV左右的开路电压.     

Morphology and magnetic properties of diluted magnetic semiconductor 1D nanostructure Ni(x)Sn(1-x)O(2-delta)

SnO2 and Ni(x)Sn(1-x)O(2-delta) (x = 0.007-0.043) 1D nanostructures are fabricated using a catalyzer assisted chemical vapor deposition (CVD). The morphology of the 1D nanostructure is sensitive to the fabrication conditions. As the Ar flux rate is decreased from 50 sccm to 40 sccm, the 1D nanostructure changes from nanowire to nanobelt. All of the Ni(x)Sn(1-x)O(2-delta) 1D nanostructures exhibit room temperature ferromagnetism (RTFM). With the increasing x, magnetic moment per Ni ion increases at first, reaches a maximum of 3.33 microB in x = 0.025, then decreases. The results of annealing in vacuum and oxidizing atmospheres reveal that oxygen vacancies play a crucial role in introducing ferromagnetism, which implies that the origin of RTFM can be understood by the bound magnetic polaron model (BMP).     

快速热处理对(Ba,Sr)TiO3薄膜晶化行为的影响

采用射频溅射法在Si(111)基片上制备了(Ba,Sr)TiO3(BST)薄膜,并对制备的薄膜进行了快速退火热处理.采用X射线衍射和原子力显微镜分析了退火温度、退火时间和加热速度对BST薄膜晶化行为的影响.研究结果表明,BST薄膜的晶化行为强烈依赖于退火温度、退火时间和加热速度.BST薄膜的结晶度随退火温度的升高而提高.适当的热处理可降低BST薄膜的表面粗糙度,BST薄膜的表面粗糙度随退火温度的升高经历了一个先降低后增大的过程,但退火后BST薄膜的表面粗糙度都小于制备态薄膜的表面粗糙度.BST薄膜的晶粒尺寸随退火温度的升高经历了一个先增大后减小的过程.随退火时间的延长,BST薄膜的特征衍射峰越来越强,薄膜的晶化程度越来越高.随退火时问的延长,BST薄膜的晶粒尺寸和表面粗糙度也经历了一个先增大后减小的过程.BST薄膜的晶粒大小主要由退火温度决定.高的升温速率可获得较小的晶粒.     

Influence of oxygen in the deposition and annealing atmosphere on the characteristics of ITO thin films prepared by sputtering at room temperature

Indium tin oxide (ITO) thin films have been grown onto glass substrates by sputtering at room temperature with various controlled oxygen and argon ratios used as reactive and sputter gases, respectively. After deposition, the samples have been annealed at 350 °C in the same sputtering chamber in vacuum or in air. The structure, morphology and electro-optical characteristics of the ITO coatings have been analyzed as a function of the oxygen added during deposition and of the annealing atmosphere by X-ray diffraction, atomic force microscopy, four points electrical measurements and spectrophotometry. It has been found that the as-deposited amorphous samples crystallize in the cubic structure by annealing. The optical transmittance and the electrical resistance decrease when the oxygen content in the deposition and the annealing atmosphere is reduced.     

Annealing effects of In2O3 thin films on electrical properties and application in thin film transistors

Considering practical applications in electronic devices, we studied the growth of In₂O₃ thin films on amorphous glasses by magnetron sputtering at room temperature and annealing effect on the structural and electrical properties. The vacuum annealed In₂O₃ thin films display a grain size enlargement and preferential orientation. Electrical characterization shows that the vacuum annealed In₂O₃ thin films exhibit a significant enhancement of both electron density and mobility, while air ambient annealing leads to a remarkable drop. The mechanism of the electrical characteristic changes in In₂O₃ thin films by annealing is explored by using different scattering mechanisms. Finally, a thin film transistor device using vacuum annealed In₂O₃ nano-meter thin films as active channel material is demonstrated.     

Effect of low oxygen pressure on structural and magnetic properties of quenched SrFe12O19 thin films

Strontium hexaferrite thin films have been grown on glass substrates at room temperature in oxygen environment by pulsed laser deposition method. The effect of oxygen pressure (p_o2) on the structural and magnetic properties has been investigated. The as-deposited films were found to be amorphous in nature. The crystallization of these films was achieved by annealing at a temperature of 850 °C in air. The thickness of the film increased with p_o2. The film grown at p_o2 = 0.455 Pa had a clear hexagonal structure. The values of coercivity for the films were found to increase with p_o2.     

溅射法制备Mn-Zn铁氧体薄膜的磁性与微结构

以交替真空溅射的方法使用成分分别为MnFe2O4与ZnFe2O4的双靶制备了成分变化的系列Mn1-xZnxFe2O4铁氧体薄膜,衬底为Si(100)。薄膜的成分通过控制不同靶的溅射时间来进行调整。沉积态的薄膜呈非晶结构,在真空炉中以适当的温度对薄膜进行退火之后能够得到多晶Mn-Zn铁氧体薄膜。组成成分为Mn0.5Zn0.5Fe2O4的薄膜呈现了相对最高的饱和磁化强度。同时还研究了制备条件对薄膜结构与磁性的影响,如溅射氧分压,退火真空度,退火温度及薄膜厚度等等。制备的薄膜相对于块状材料具有较高的矫顽力,进而讨论了应力对薄膜矫顽力的影响。     

Effect of post annealing on structural and optical properties of ZnO thin films deposited by vacuum coating technique

We report the effect of annealing temperature on structural, electrical and optical properties of polycrystalline zinc oxide thin films grown on p-type silicon (100) and glass substrates by vacuum coating technique. The XRD and AFM measurements confirmed that the thin films grown by this technique have good crystalline hexagonal wurtzite structures and homogenous surfaces. The study also reveals that the rms value of thin film roughness increases from 6 to 16 nm, the optical band gap increases from 3.05 to 3.26 eV and resistivity from 0.3 to 5 Ωcm when the post-deposition annealing temperature is changed from 400 to 600 °C. It is observed that ZnO thin film annealed at 600 °C after deposition provide a smooth and flat texture suited for optoelectronic applications.