| Zinc oxide (ZnO) is one of the most widely researched semiconductors in recent years. As a new generation of transparent conductive oxide thin films, it exhibits outstanding optical and electrical properties, because of high carrier concentration and wide optical band gap. Compared with In2O3, ZnO is abundant, cheap, non-toxic and stable in an atmosphere of hydrogen plasma. Transparent conductive oxide thin films doped with suitable Al have more excellent optical and electrical properties, and are widely applied to various electrical and optical devices including liquid crystal display, solar cell, hot mirror and surface acoustic wave devices as transparent conductive oxide electrodes.Dissemination of high-capacity integrated thin film capacitor as the basic unit of capacitance RC network is widely used in complex circuits; it also can be used as dynamic memory storage device, or DRAMs free storage unit used to make computer chips. Quaternary compounds Sr0.5Ba0.5TiO3(SBTO) is one of new dielectric materials, because of its high dielectric constant, low dielectric loss and the advantages of low leakage current density. The film capacitor materials in integrated as high capacity storage media have great application background.In this paper, microstucture of ZAO with different doping transparent thin films which deposited on glass substrates by sol-gel method, and deposition LaAlO3substrates of Sr0.5Ba0.5TiO3/La0.5Sr0.5CoO3film by pulsed laser deposition method were studied by XRD, TEM, HTEM, and interoperated their growth mechanism.The results obtained ZnO thin films deposited on glass substrates by sol-gel method and annealed at500℃, can not form c-axis oriented columnar grains. It forms by the irregular stacking round grains. Grain size is about100nm. It tends to grow vertically and contains a large number of stacking faults.(002) oriented grains is more than other orientation in the whole sample. Al-doped ZnO thin film has a distinct layered structure compared with the pure ZnO thin films. The grain size of each interface is larger and has deep contrast. The grain size of other part is very small, only a few nanmeters. With the increasng of Al doping, the grain size becomes uniform. Al is able to enter ZnO crystal lattice which makes the ZnO lattice change, a-axis increases and c-axis decreases. With the increase of Al content, in the ZnO grain boundary precipitation of amorphous Al2O3prevents the ZnO grain growth, according to the hierarchical structure. High Al-doping concentration formed the large-size grains on each interface, is due to dry conditions at300℃. ZnO occurred at each priority uneven surface nucleation, and the ups and downs with the surface, the grain aggregate. Compared to other parts, they have high purity without amorphous Al2O3in the interface, and can grow at500℃.Prepared SBTO/LSCO/LAO film systems by PLD, LSCO layers have different bulk materials and the new structure which is due to cation occupying according to A position. Its structure changes to tetragonal symmetry from the face-centered cubic. There are a lot of the orientation domains in the LSCO thin films, the c-axis of the domain along the substrate LAO are three pseudo-cubic axis, so the entire film is composed of three orientation domains. There are two typical domain interface, respectively (110) and (100). In the LSCO/LAO interface only has [001] type orientation domain growth and forms AlO-LaO-CoO2-SrO-CoO2-LaO interface states. The interface of LSCO film and substrate has few dislocations, the film stress is completely contained by lattice deformation. The substrate and the target into a certain angle can obtain a very complete LSCO films. For the smooth and rough surface of the bottom electrode, the crystallinity of the LSCO has a great impact to the structure of SBTO thin film. SBTO film can form two kinds of growth patterns, which can be expressed as full extension and local extension growth. |
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