脉冲准分子激光淀积薄膜的实验研究

利用两种脉宽(30ns,500fs)的KrF准分子激光展开了淀积类金刚石薄膜的实验研究,并且成功地制备了大面积不含氢成分的HF-DLC薄膜,运用时空分辨的等离子体发射光谱诊断系统和离子探针系统研究了等离子体特性对薄膜性能的影响。尝试了利用准分子激光制备非晶硅薄膜,研究了实验参数对非晶硅薄膜制备的影响,并分析了制备具有良好电学和光学性能的非晶硅薄膜的条件。     

脉冲准分子激光淀积薄膜的实验研究

 利用两种脉宽(30ns，500fs)的KrF准分子激光展开了淀积类金刚石薄膜的实验研究，并且成功地制备了大面积不含氢成分的HF-DLC薄膜，运用时空分辨的等离子体发射光谱诊断系统和离子探针系统研究了等离子体特性对薄膜性能的影响。尝试了利用准分子激光制备非晶硅薄膜，研究了实验参数对非晶硅薄膜制备的影响，并分析了制备具有良好电学和光学性能的非晶硅薄膜的条件。     

XeCl（308nm）脉冲准分子激光淀积类金刚石薄膜

利用ＸｅＣｌ（３０８ｎｍ）脉冲准分子激光淀积技术在功率密度５×１０８Ｗ／ｃｍ２、室温、真空度１０－３Ｐａ的条件下，制备出不含氢成分的类金刚石薄膜，研究了类金刚石薄膜的特性及其随制备工艺条件的变化规律。研究了激光诱导的碳等离子体发射光谱，探讨了类金刚石薄膜的形成机理。     

脉冲激光淀积高温超导薄膜

１９８７年贝耳实验室首次用脉冲准分子激光制备出高温超导薄膜以后，脉冲激光淀积技术获得了长足的发展，现在已成为最好的薄膜制备技术之一．文章简要介绍了用脉冲激光淀积技术制备高温超导薄膜的原理、特点及发展情况．     

超短脉冲准分子激光淀积类金刚石薄膜的实验研究

利用ＫｒＦ超短脉冲激光器开展了超短脉冲激光淀积金刚石薄膜实验研究,薄膜生长速率０．０２ｎｍ／ｐｕｌｓｅ,厚度０．５－０．６μｍ,显微硬度５５ＧＰａ,光学透过率优于９０％,采用等离子本的时间－空间分辨的发射光谱技术,给出了等离子体的粒子成份以及等离子体的时间－空间的演化图像,以及在不同激光参数条件下等离子体特性的变化,发现超短脉冲激光的等离子体有能量高、持续时间短（高通量）的特点,适合类金刚石薄膜的     

脉冲激光淀积高温超导薄膜的几个技术问题

本文对脉冲激光法（ＰＬＤ）制备高温超导薄膜过程中的几个技术问题做了简要介绍     

准分子激光扫描消融淀积大尺寸超导薄膜

利用我们设计的一套光学变换传输系统实现了激光束在超导靶上一定范围内扫描消融来淀积高T_c超导薄膜。实验表明用这种激光扫描消融方法可使大尺寸超导薄膜的厚度均匀性得到较大的改善。我们采用激光扫描半径为9mm在12mm×33mm的Y-ZrO₂基片上淀积出零电阻温度T_c≥90K,临界电流密度J_c(零磁场,77K)≥1×10⁶A/cm²,薄膜c轴择优取向,厚度均匀性较好的YBa _关键词：     

淀积气压对脉冲激光淀积La掺杂钛酸铅薄膜介电性能的影响

利用脉冲激光淀积法在Pt/Ti/SiO2/Si衬底上制备了28mol%La掺杂钛酸铅薄膜.采用不同的淀积氧气压，并分析了其对薄膜微观结构和介电性能的影响.结果表明，在2Pa左右的气压下淀积的薄膜具有好的结晶度和介电系数.在频率为10kHz时28mol%La掺杂钛酸铅薄膜的介电系数达852，并且保持了较低的损耗.同时制备了其他La掺杂浓度的PbTiO3薄膜，发现它们也有类似的特点.对此作了定性解释. 关键词： 脉冲激光淀积 PLT薄膜 气压 介电增强     

用脉冲激光淀积制备具有光滑表面的A-轴取向YBa2Cu3O7薄膜

我们采用脉冲激光淀积方法在(100)SrTiO3基底上制备了a-轴取向外延的YBa2Cu3O7-x薄膜.通过采用活性氧,降低氧压和淀积速率,制备出了Tc超过80K、表面平均粗糙度为4.43nm的薄膜.X-射线衍射谱表明,实验得到的YBa2Cu3O7-x外延薄膜是高度A-轴取向的.     

Characterization of zirconium thin films deposited by pulsed laser deposition

Zirconium(Zr) thin films deposited on Si(100) by pulsed laser deposition(PLD) at different pulse repetition rates are investigated. The deposited Zr films exhibit a polycrystalline structure, and the X-ray diffraction(XRD) patterns of the films show the α Zr phase. Due to the morphology variation of the target and the laser–plasma interaction, the deposition rate significantly decreases from 0.0431 /pulse at 2 Hz to 0.0189 /pulse at 20 Hz. The presence of droplets on the surface of the deposited film, which is one of the main disadvantages of the PLD, is observed at various pulse repetition rates. Statistical results show that the dimension and the density of the droplets increase with an increasing pulse repetition rate. We find that the source of droplets is the liquid layer formed under the target surface. The dense nanoparticles covered on the film surface are observed through atomic force microscopy(AFM). The root mean square(RMS) roughness caused by valleys and islands on the film surface initially increases and then decreases with the increasing pulse repetition rate.The results of our investigation will be useful to optimize the synthesis conditions of the Zr films.     

Growth and characterization of pulsed laser deposited ZnO thin films

One of the most important and promising materials from metal oxides is ZnO with specific properties for near UV emission and absorption optical devices. The properties of ZnO thin films strongly depend on the deposition method. Among them, pulsed laser deposition (PLD) plays an important role for preparing various kinds of ZnO films, e.g. doped, undoped, monocrystalline, and polycrystalline. Different approaches — ablation of sintered ZnO pellets or pure metallic Zn as target material are described. This contribution is comparing properties of ZnO thin films deposited from pure Zn target in oxygen atmosphere and those deposited from sintered ZnO target. There is a close connection between final thin film properties and PLD conditions. The surface properties of differently grown ZnO thin films are measured by secondary ion mass spectrometry (SIMS), atomic force microscopy (AFM) and scanning electron microscopy (SEM). Furthermore, different approaches — ablation of sintered ZnO pellet or pure metallic Zn as target materials are described. The main results characterize typical properties of ZnO films versus technological parameters are presented. Presented at 5-th International Conference Solid State Surfaces and Interfaces, November 19–24, 2006, Smolenice Castle, Slovakia     

Nanostructured silver thin films deposited by pulsed laser ablation

Nanostructured thin films were deposited by excimer laser ablation of silver targets in controlled atmospheres of He and Ar. The film structural properties were investigated by means of scanning electron microscope and transmission electron microscope imaging. The film growth mechanism was identified as the result of coalescence of nanometric clusters formed during plume flight. Cluster formation involves plume confinement as a consequence of the increased collisional rate among plasma species. Fast photography imaging of the laser-generated silver plasma allowed to identify plasma confinement, shock wave formation and plasma stopping.     

脉冲激光气相沉积法制备的非晶CH薄膜特性分析

采用脉冲激光气相沉积(PLD)法,研究了氢气压强对非晶CH薄膜性能的影响。原子力显微镜图和白光干涉图显示,薄膜表面平整致密,随着氢气压强增大,粗糙度变大。拉曼光谱分析表明,氢气压强增加,G峰和D峰位置都在向高波数方向移动。傅里叶变换红外光谱分析显示,薄膜中存在sp3—CH2和sp2—CH等基团。最后,采用PLD漂浮法在最优参数氢气压强为0.3 Pa下,成功制备了不同厚度（100~300 nm）、满足一定力学强度、无明显宏观缺陷的自支撑CH薄膜。     

激光烧蚀溅射沉积薄膜的研究现状

激光烧蚀溅射沉积薄膜技术是一项新的固体薄膜制造技术.文内简单地介绍了这项技术产生的历史背景、进化过程;根据相关文献,详细描述了这项技术的原理;基于最新资料,全面讨论了这项技术的国内外研究现状;总结了该技术的优、缺点;客观评价了该技术的应用前景和研究意义;并对该技术的今后研究方向提出了建议.     

Effects of the substrate temperature on the bioglass films deposited by pulsed laser

Effects of the substrate temperature on the bonding configuration and adhesion strength of the bioglass films deposited by pulsed laser were investigated by Fourier transform infrared spectroscopy (FTIR) and scratch apparatus. Morphology of the films is compact with the particles on the surface of them and the structure is amorphous glass. Bonding configuration is different from that of the target. Si-O-NBO/Si-O-Si (s) intensity ratios of the films decline as compared with the target. Besides, this tendency is obvious as the substrate temperature decreases. This effect is attributed to the network rearrangement during the film growth, which is associated to special structure of glass and complex physical mechanisms of pulsed laser deposition (PLD). Scratch test results show that the film deposited at 200 °C has the highest adhesion strength.     

Diamond-like phase formation in an amorphous carbon films prepared by periodic pulsed laser deposition and laser irradiation method

Diamond-like carbon (DLC) films were fabricated by pulsed laser ablation of a liquid target. During deposition process the growing films were exited by a laser beam irradiation. The films were deposited onto the fused silica using 248 nm KrF eximer laser at room temperature and 10⁻³ mbar pressure. Film irradiation was carried out by the same KrF laser operating periodically between the deposition and excitation regimes. Deposited DLC films were characterized by Raman scattering spectroscopy. The results obtained suggested that laser irradiation intensity has noticeable influence on the structure and hybridization of carbon atoms deposited. For materials deposited at moderate irradiation intensities a very high and sharp peak appeared at 1332 cm⁻¹, characteristic of diamond crystals. At higher irradiation intensities the graphitization of the amorphous films was observed. Thus, at optimal energy density the individual sp³-hybridized carbon phase was deposited inside the amorphous carbon structure. Surface morphology for DLC has been analyzed using atomic force microscopy (AFM) indicating that more regular diamond cluster formation at optimal additional laser illumination conditions (∼20 mJ per impulse) is possible.     

脉冲激光沉积动力学研究进展

脉冲激光沉积技术是现代常用的先进薄膜材料制备技术之一.文章在简要介绍脉冲激光沉积技术及其进展的基础上,较全面地介绍了脉冲激光沉积动力学的基本物理图像和动力学构架,深入地探讨了激光烧蚀靶材过程、等离子体膨胀过程和薄膜沉积过程的动力学规律,阐述了我国学者在脉冲激光沉积动力学研究方面的贡献,例如包括脉冲激光沉积三个工艺过程自洽的统一模型,等离子体膨胀的冲击波模型,基于局域能量动量守恒定律的新等离子体演化动力学模型,包括热源项、蒸发项、等离子体屏蔽效应和动态物性参数的烧蚀热传导模型,考虑电子碰撞效应和能带结构变化的修正双温模型,能统一描写从纳秒级到飞秒级脉冲激光烧蚀规律的统一双温模型等.     

Structural and optical properties of ZnO thin films deposited on quartz glass by pulsed laser deposition

ZnO thin films with typical c-axis (0 0 2) orientation were successfully deposited on quartz glass substrates by pulse laser ablation of Zn target in oxygen atmosphere at a relatively low temperature range of 100-250 °C. The structural and optical properties of the films were studied. In photoluminescence (PL) spectra at room temperature, single ultraviolet emission (without deep-level emission) was obtained from ZnO film deposited at the temperature of 200 °C. This was attributed to its low intrinsic defects.