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采用实际的生长模型和物理参量,用Monte Carlo方法对高温下金属薄膜的生长过程进行了模拟研究.综合考虑了原子沉积、扩散、成核、生长和扩散原子的再蒸发、原子沿岛周界扩散和岛的合并等众多过程后,模拟得到与实验结果相当一致的薄膜生长形貌及其相应的定量结果.通过动态统计薄膜生长过程中的岛数目及薄膜生长率,得到实验中不易直接获得的高温下薄膜生长的许多细节,如岛数目和薄膜生长率随表面温度、覆盖度变化的详细情况等
关键词:
薄膜
Monte Carlo模拟
成核
岛密度
薄膜生长率 相似文献
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利用仿真方法从原子尺度研究薄膜生长过程是当前薄膜研究领域的热点. 目前, 仿真方法主要在纳米尺度模型实现, 时空需求很大. 针对这一问题, 本文提出元胞和蒙特卡洛相结合的模拟方法, 实现对微米尺度模型薄膜生长过程的模拟. 利用元胞方法来实现模型表示以及演化计算, 从而降低对内存空间的要求, 提高计算效率, 并使用蒙特卡洛方法计算粒子的扩散概率. 通过对氮化硅薄膜生长过程进行具体研究, 将模拟结果与实际实验结果和分子动力学演化结果进行表面形貌和成分的比较, 验证了该方法的有效性. 相似文献
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利用Monte Carlo (MC)模拟技术研究了非均一的吸附原子与基底相互作用能在一定的生长条件下对超薄膜生长过程的影响.非均一相互作用能是由基底表面原子在垂直和水平方向上实际位置与理想晶格原子位置的偏差所造成.本文用高斯分布来表示这种非均一相互作用能.模拟结果表明:非均一相互作用能对超薄膜的生长过程及薄膜的形貌有显著的影响.这种影响同时受到生长条件的限制,在中等温度时相互作用能的非均一性对岛的个数、平均大小的影响最显著;温度的增加在一定程度上可抵御相互作用能的非均一性对薄膜生长的影响.
关键词:
薄膜生长
Monte Carlo 模拟
相互作用能 相似文献
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利用分子动力学模拟方法,从原子尺度上研究了类金刚石(DLC)薄膜生长过程. 按照运动特点把入射原子在表面的行为分为表面冷冻、迁移、注入和反弹等四种,并由此提出原子运动模型. 入射原子的表面行为对DLC薄膜的微观结构以及生长方式有重要影响. 其中原子水平迁移是薄膜热弛豫的主要途径,入射原子的注入和迁移行为相互竞争,决定了薄膜生长的模式和最终结构. 利用统计分析手段给出了入射能量对原子表面行为进而对薄膜结构的影响,加深了对DLC薄膜生长机理的认识. 相似文献
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用动态Monte-Carlo方法对Ge在单层表面活性剂Pb覆盖的Si(111)表面上沿团簇边缘扩散进行三维模拟.重点讨论Ge原子是否沿团簇边缘扩散,沿边缘扩散时的最大扩散步数及最近邻原子数对三维生长的影响,并计算薄膜表面粗糙度研究三维生长模式.模拟表明Ge沿团簇边缘扩散的行为对薄膜生长模式的影响很大,同时讨论了ES势对三维生长模式的影响. 相似文献
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利用Monte Carlo方法研究了基底显微结构对薄膜生长的影响. 对不同显微结构基底上薄膜生长的初始阶段岛的形貌和尺寸与薄膜覆盖度和入射粒子沉积速率之间的关系进行了模拟和分析. 模型中考虑了粒子沉积、吸附粒子扩散和蒸发等过程. 结果表明,基底显微结构对薄膜生长具有明显影响. 当沉积温度为300K、沉积速率为0.005ML/s(Monolayer/second,简称ML/s)、覆盖度为0.05ML时,四方基底上薄膜生长呈现凝聚生长. 随着覆盖度增加,岛的尺寸变大,岛的数目减少. 而对于六方基底,当覆盖度从0.05ML变化到0.25ML时,薄膜生长经历了一个从分散生长过渡到分形生长的过程. 无论是四方还是六方基底,随着沉积速率的增加,岛的形貌由少数聚集型岛核分布状态向众多各自独立的离散型岛核分布状态过渡. 相似文献
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设计了一套具有一定实用意义和科学价值的薄膜生长荧光显微图像实时采集与分析系统,可以实现透明衬底上有机荧光分子薄膜生长的实时原位监测。进一步阐明了系统的硬件构筑思路和软件设计架构,并依据薄膜的形貌特征,给出8个主要生长信息参数及其求取算法,并利用自行搭建的实验系统,针对联六苯(p-6P)分子在云母衬底上的纳米纤维生长过程,得出了其准一维的线性生长规律。该系统作为重要的薄膜生长成像监测技术,有望在薄膜与衬底表面相互作用和衬底微区结构特性研究等方面起到积极的作用。 相似文献
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MgO(111)上NbN和AlN薄膜的生长研究 总被引:2,自引:0,他引:2
在制备NbN/AlN/NbN隧道结的工艺过程中,为了获得具有优质单晶结构的NbN薄膜,我们在MgO(111)基片上探索了直流溅射法制备NbN薄膜的生长工艺条件,XRD研究分析表明,我们获得了单晶结构良好的NbN薄膜;为了支持作为上电极的NbN薄膜的生长,也需要良好的AlN薄膜用作势垒层,我们采用射频磁控溅射设备和纯净的Al靶对AlN薄膜进行了制备研究.实验结果表明,所获得的AlN薄膜具有六方c-轴取向,并讨论了衬底和薄膜界面处可能的结构情况. 相似文献
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Basing on some growth models of thin film, we have investigated the growth mechanism of glancing angle deposition (GLAD) film. The simulation verifies that the overhangs/vacancies also contribute to the columnar growth as well as the self-shadowing effect for GLAD thin film. Besides, we have studied the effect of the deposition rate, surface and bulk diffusions on the microstructure of thin film using the time-dependent Monte Carlo method. The results show that the surface and bulk diffusions can significantly enhance the packing density of thin film in GLAD growth, and the increase of the deposition rate induce the moderate decrease of the packing density. 相似文献
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Shinho Cho 《Current Applied Physics》2013,13(9):1954-1959
Eu-doped ZnO (EZO) thin films were prepared on glass substrates at various growth temperatures by radio-frequency magnetron sputtering. The properties of deposited thin films showed a significant dependence on the growth temperature. The preferential growth orientation of all the thin films was occurred along the ZnO (002) plane. The maximum crystallite size and the minimum average transmittance in the wavelength range of 450–1100 nm were observed for the EZO thin film deposited at 25 °C. A red shift of the optical band gap was observed in the growth temperature range of 25–300 °C. The highest figure of merit, an index for evaluating the performance of transparent conducting thin films, was obtained at 200 °C of growth temperature. These results indicated that the high-quality EZO film was obtained at a growth temperature of 200 °C. 相似文献
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We demonstrate combinatorial approach in investigation of organic thin film fabrication. “Combinatorial substrate screening”, which is the deposition onto several kinds of substrates simultaneously, is useful to choose suitable substrate for organic thin film growth. “Combinatorial thickness-gradient films” can be fabricated using a moving mask which travels from an edge to another edge of substrate continuously during the deposition. The combinatorial thickness-gradient film can be regarded as the library for time evolution of film growth during the deposition. This mapping can serve as a powerful method for the research of growth of thin film in an initial stage. Besides, combinatorial thickness-gradient film can be utilized for the examination of a buffer layer effect. These techniques enable us to quickly optimize for the fabrication of high-quality organic thin films. 相似文献
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The thin film growth has been confirmed to be assembled by an enormous number of clusters in experiments of CVD. Sequence of clusters’ depositions proceeds to form the thin film at short time as gas fluids through surface of substrate. In order to grow condensed thin film using series of cluster deposition, the effect of initial velocity, substrate temperature and density of clusters on property of deposited thin film, especially appearance of nanoscale pores inside thin film must be investigated. In this simulation, three different cluster sizes of 203, 653, 1563 atoms with different velocities (0, 10, 100, 1000 and 3000 m/s) were deposited on a Cu(0 0 1) substrate whose temperatures were set between 300 and 1000 K. Four clusters and one cluster were used in primary deposition and secondary deposition, respectively. We have clarified that adhesion between clusters and substrate is greatly influenced by initial velocity. As a result, the exfoliation pattern of deposited thin film is dependent on initial velocity and different between them. One borderline dividing whole region into porous region and nonporous region are obtained to show the effect of growth conditions on appearance of nanoscale pores inside thin film. Moreover, we have also shown that the likelihood of porous thin film is dependent on the point of impact of a cluster relative to previously deposited clusters. 相似文献
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利用脉冲激光沉积技术在非晶石英衬底上制备立方结构MgZnO薄膜,并研究MgZnO薄膜结晶特性、光学带隙随生长温度的变化情况。当生长温度从150℃升高到700℃时,MgZnO薄膜的生长取向由(200)向(111)转变。在600℃以下,MgZnO薄膜光学带隙的变化规律与晶格中Mg和Zn原子比例的变化趋势是一致的;而当温度升至700℃时,虽然MgZnO晶格中Mg和Zn原子比例降低,但由于平均晶粒尺寸变大,薄膜的光学带隙反而上升。在300℃和700℃晶格匹配的情况下,获得了单一(200)和(111)取向的立方MgZnO薄膜。 相似文献
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TiB2 thin film was deposited by laser-arc deposition method on the surface of single crystalline silicon. The morphology, composition, structure and microtribological properties of the film were studied by using XPS, XRD and atomic force/friction force microscope (AFM/FFM). The results show that TiB2 (100) preferred growth on the Si(100)substrate, TiB2(001) preferred growth on the Si(111) substrate. The TiB2 thin film was composed of TiB2 and a small amount of TiO2. The friction coefficient of TiB2 film on substrates Si (100) and Si(111) in microtribological process were 0.087 and 0.073,respectively. TiB2 thin film displayed distinct ability of anti-scratch and wear-resistance. 相似文献
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N. Schell R.M.S. Martins F.M. Braz Fernandes 《Applied Physics A: Materials Science & Processing》2005,81(7):1441-1445
The real-time structural design of magnetron sputtered NiTi SMA (shape memory alloy) thin films is reported. During deposition the phase content was followed in-situ by synchrotron X-ray diffraction and controlled by varying the power of co-sputtering NiTi plus Ti for otherwise fixed deposition parameters. This method allows an optimization of the thin film in respect to its functional properties like phase transition temperature or adhesion, as well as an understanding of the actual growth process by revealing temporary intermediate growth states (different phases and precipitates) and diffusion processes during film growth. PACS 81.15.Cd; 61.10.Nz; 68.55.Jk 相似文献