磁控溅射技术进展及应用(上)

近年来磁控溅射技术的应用日趋广泛,在工业生产和科学研究领域发挥巨大作用。随着对具有各种新型功能的薄膜需求的增加,相应的磁控溅射技术也获得进一步的发展。本文将介绍磁控溅射技术的发展,以及闭合磁场非平衡溅射、高速率溅射及自溅射、中频及脉冲溅射等各种新技术及特点,阐述磁控溅射技术在电子、光学、表面功能薄膜、薄膜发光材料等许多方面的应用。     

磁控溅射技术进展及应用(下)

近年来磁控溅射技术的应用日趋广泛,在工业生产和科学研究领域发挥巨大作用。随着对具有各种新型功能的薄膜需求的增加,相应的磁控溅射技术也获得进一步的发展。本文将介绍磁控溅射技术的发展,以及闭合磁场非平衡溅射、高速率溅射及自溅射、中频及脉冲溅射等各种新技术及特点,阐述磁控溅射技术在电子、光学、表面功能薄膜、薄膜发光材料等许多方面的应用。     

脉冲激光沉积薄膜的残余应力测量

为了测量脉冲激光沉积法制备的小面积薄膜的残余应力,并解决Stoney公式在特定情况下误差较大的问题,本文提出了一种基于悬臂梁结构和数值计算的薄膜残余应力测量方法。该方法以初始曲率为零的原子力显微镜探针作为衬底梁,在衬底梁上使用脉冲激光沉积方法沉积被测薄膜,并记录衬底梁在薄膜沉积前后的翘曲形貌变化,再结合薄膜厚度、衬底梁几何尺寸、所涉及材料的杨氏模量与泊松比等其他参数,借助数值计算对实验数据进行分析,得出被测薄膜的残余应力。使用该方法测出:基于脉冲激光沉积法在高温环境下制备的二氧化钒薄膜的残余应力为-340 MPa,与文献报道的结果相符。本文提出的基于悬臂梁结构和数值计算的薄膜残余应力测量方法具有适用范围广、准确度好、实验成本低的优点。     

脉冲激光真空弧薄膜制备技术

本文首先介绍了脉冲激光蒸发沉积以及真空弧沉积技术，在此基础上对激光真空弧技术的原理、特点、研究现状及应用进行了文献综述。可以预测，激光真空弧技术在薄膜材料科学与技术以及工业生产中必将具有广阔应用前景。     

基于离子束溅射Ta2O5薄膜的紫外吸收膜技术

为获得高性能紫外激光薄膜元件,急需研制紫外高反射吸收薄膜,实现吸收损耗的精确测量。本文采用离子束溅射技术,通过调控氧气流量实现了具有不同吸收的Ta_2O_5薄膜的制备。以Ta_2O_5薄膜作为高折射率材料,设计了355nm的紫外高反射吸收薄膜。采用离子束溅射沉积技术,在熔融石英基底上制备了355nm的吸收薄膜,对于A=5%的紫外吸收光谱,在355nm的透射率、反射率和吸收率分别为0.1%,95.0%和4.9%;对于A=12%的紫外吸收光谱,在355nm的透射率、反射率和吸收率分别为0.1%,87.4%和12.5%。实验结果表明,采用离子束溅射沉积技术,可以实现不同吸收率的355nm高反射吸收薄膜的制备,对于基于光热偏转测量技术的紫外光学薄膜弱吸收测量仪的定标具有重要的意义。     

超薄铝膜的制备与透光率的研究

当铝(Al)膜的厚度在100nm时,可以作为一种光学薄膜使用.用这种超薄铝膜制成光学元件具有耐激光以及损耗小等特点,在大功率激光系统中将得到应用.利用高纯铝靶,运用直流磁控溅射法制备了超薄铝膜,利用双光束分光光度计研究了其光学性质,测试了超薄铝膜的制备条件,如工作压强、靶基距、溅射时间等对薄膜的光学性质的影响.得到了工作压强、靶基距及溅射功率与薄膜的光学性质之间的关系.     

脉冲激光溅射及富-锆PZT薄膜的性能研究

采用脉冲激光溅射方法将PZT/YBCO沉积在LaAlO3(LAO)基底上,所选择的烧结靶材是Pb(Zr0.94Ti0.06)O3+2%Bi2O3.沉积YBCO和PZT薄膜的基底温度分别为710℃和570℃.整体结构PZT/YBCO/LAO在600℃的基底温度下退火15min.本文通过X射线衍射分析观察了薄膜的结晶状态,利用P-V曲线估计PZT薄膜的电学性质,并测量出薄膜的介电常数与频率(ε-f)以及介电损耗与频率(tanδ-f)的关系曲线.     

掺杂对富-锆Pb(ZrxTi1-x)O3薄膜性能的影响

采用脉冲激光溅射方法将PZT/YBCO沉积在LaAlO3(LAO)基底上,所选择的烧结靶材分别是不掺杂的Pb(Zr0.94Ti0.06)O3和掺有2%Bi2O3的Pb(Zr0.94Ti0.06)O3.沉积这两种薄膜时所选择的工艺参数均相同.通过X射线衍射分析比较了两种薄膜的结晶状态,利用P-V曲线比较了两种薄膜的电学性质,并测量出这两种薄膜的介电常数与频率(ε-f)以及介电损耗与频率(tanδ-f)的关系曲线.     

射频溅射工艺对WSx薄膜摩擦性能的影响

采用射频溅射法以3Cr13马氏体不锈钢为基片制备了硫化钨薄膜.通过物相分析和表面形貌观察,以及测定微区化学成分、结合力和摩擦因数,研究了溅射功率、工作压力和沉积时间等溅射工艺条件对薄膜摩擦性能的影响.结果表明通过射频溅射法可获得非晶态WSx薄膜,薄膜的S/W比一般小于2,并受溅射工艺影响较为明显,随溅射功率的升高逐渐降低,随溅射时间的延长明显升高.薄膜结合力受溅射工艺影响并不显著.通过射频溅射所获得薄膜的摩擦因数在一定范围内与其硫钨比成反比.     

结晶氮化碳薄膜

由武汉化工学院研究的“脉冲电弧放电电离有机溶液制备 (类 )金刚石薄膜”装置 ,不久前调试成功。用此装置可以高质量地沉淀出一种物理性能和金刚石相比的材料——氮化碳结晶。氮化碳晶体具有高硬度、宽带隙、高热导率和低摩擦系数等优点 ,在机械和光电子及军事等领域具有巨大的应用前景。目前合成氮化碳薄膜的实验方法主要有激光烧蚀石墨靶 ,反应溅射 ,等离子体化学气相沉积和离子注入等。该发明采用脉冲电弧放电等离子体技术 ,可以在大气压环境、2 0 0℃～ 30 0℃的衬底温度下 ,合成晶态氮化碳薄膜 ,薄膜的沉积速率可达 3μm/h～ 5μm/h。…     

Structural properties of 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 relaxor ferroelectric thin films on SrRuO3 conducting oxides

Coating of 0.65Pb(Mg(1/3)Nb(2/3))O(3)-0.35PbTiO(3) (PMN-PT) relaxor ferroelectrics by a sol-gel method is followed by growth of epitaxial SrRuO(3) (SRO) metallic oxide electrodes on SrTiO(3) (STO) single-crystal substrate by pulsed laser deposition. High-quality PMN-PT films on SRO with preferred growth orientation were successfully fabricated by controlling the operation parameters. Structural properties of relaxor ferroelectric PMN-PT thin films on SRO/STO substrates have been studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM). In-plane and out-of-plane alignments of the heterostructure are confirmed and the structural twinning of the materials are also revealed.     

Mirrorlike pulsed laser deposited tungsten thin film

Mirrorlike tungsten thin films on stainless steel substrate deposited via pulsed laser deposition technique in vacuum (10(-5) Torr) is reported, which may find direct application as first mirror in fusion devices. The crystal structure of tungsten film is analyzed using x-ray diffraction pattern, surface morphology of the tungsten films is studied with scanning electron microscope and atomic force microscope. The film composition is identified using energy dispersive x-ray. The specular and diffuse reflectivities with respect to stainless steel substrate of the tungsten films are recorded with FTIR spectra. The thickness and the optical quality of pulsed laser deposition deposited films are tested via interferometric technique. The reflectivity is approaching about that of the bulk for the tungsten film of thickness ～782 nm.     

Structural properties of 0.65Pb(Mg1/3Nb2/3)O3–0.35PbTiO3 relaxor ferroelectric thin films on SrRuO3 conducting oxides

Coating of 0.65Pb(Mg_1/3Nb_2/3)O₃–0.35PbTiO₃ (PMN–PT) relaxor ferroelectrics by a sol–gel method is followed by growth of epitaxial SrRuO₃ (SRO) metallic oxide electrodes on SrTiO₃ (STO) single-crystal substrate by pulsed laser deposition. High-quality PMN–PT films on SRO with preferred growth orientation were successfully fabricated by controlling the operation parameters. Structural properties of relaxor ferroelectric PMN–PT thin films on SRO/STO substrates have been studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM). In-plane and out-of-plane alignments of the heterostructure are confirmed and the structural twinning of the materials are also revealed.     

脉冲多弧离子源的研制

脉冲多弧离子源主要用来镀制类金刚石薄膜及金属、合金膜,研究了脉冲多弧离子源的引弧方法、放电的稳定性、离子源结构对镀膜均匀性的影响。在此基础上,研制了脉冲多弧离子源,利用该源镀制了类金刚石薄膜及镍铬铁合金渐变膜。经测试,膜层性能良好。     

Nanoscale surface electrical properties of zinc oxide films investigated by conducting atomic force microscopy

In this study, conducting atomic force microscopy was employed to investigate the nanoscale surface electrical properties of zinc oxide (ZnO) films prepared by pulsed laser deposition (PLD) at different substrate temperatures for use as anode materials in polymer light-emitting diodes. The results show that the surface conductivity distribution of ZnO is related to its surface structure. At substrate temperatures of 150-200 degrees C, the conducting regions may cover over 90% of the ZnO thin-film surface, thus providing the best local conductivity. Moreover, heating at substrate temperatures of above 250 degrees C can effectively make the conductivity on the ZnO surface uniform. In particular, at substrate temperatures of around 300 degrees C, the conducting regions where currents are between 1 and 2 muA may cover as much as 83% of the surface, and furthermore, the transmission ratio in the visible range is higher than 80%. This is a rather ideal production temperature for the PLD for ZnO films.     

Influence of target grit count and sintering temperature on pulsed laser deposition of SiC thin films

A pulsed laser deposition (PLD) technique for depositing SiC on Si(100) substrates using Nd³⁺:YAG laser at 355 nm is studied. The influence of substrate temperature, ambient pressure, and SiC powder grit size on both structure and morphology of SiC thin film is investigated. Further, the influence of the target preparation on the reduction of droplet formation during Nd³⁺:YAG laser-assisted pulsed laser deposition of SiC thin films is investigated. Experimental studies show that multicrystalline SiC film can be obtained with temperature ranging from 600 to 700 °C and at an ambient pressure of about 5.5 × 10^?3 Pa. Further, droplet formation on the deposited film was reduced significantly by selecting the grit count of SiC powder 500 and the pressure of 2 × 10^?2 Pa. SiC target sintered at 1,600 °C showed a reduced wear during the laser ablation. The X-ray diffraction (XRD) and the Raman spectroscopy studies on deposited films clearly show the multicrystalline (combined 3C-SiC and 4H-SiC) nature of SiC films. I-V characteristics of deposited SiC film on n-type c-Si substrate also indicated that SiC thin film possesses P-type semiconductor properties.     

Pulsed laser atom probe analysis of semiconductor materials

As the size of semiconductor devices is reduced the active volumes of material in each device is also decreased. Under these circumstances it becomes more important to understand the microchemistry of semiconducting materials, as small fluctuations in composition can dramatically affect both the operation of the devices, and of the contacts to semiconductors. Atom probe microanalysis has been shown to be able to analyse the microchemistry of metallic materials with plane-by-plane resolution, and by using a pulsed laser to replace the more conventional voltage pulses the analysis of semiconducting and insulating materials becomes possible. The pulsed laser atom probe has been shown to give very accurate chemical analysis of the stoichiometry of extremely small volumes of III-V compound semiconductors, and the composition of the interfacial layer between silicon dioxide and silicon has been identified as SiO of thickness about 0.3 nm. It has been shown to be possible to prepare specimens for analysis from thin films of semiconductors, thus allowing the microanalysis of a wide range of materials that are deposited in thin film form.     

蓝宝石镀膜方法研究

蓝宝石具有一系列优异的光学和力学性能,使其在现代镀膜领域中倍受青睐。在一些高科技领域中,蓝宝石作为重要的功能材料,为实现不同的功能,选择不同的镀膜材料来实现。介绍了蓝宝石的主要物理性能,并对其作为衬底的几种镀膜方法作了简单介绍,包括磁控溅射法、脉冲激光沉积法、金属有机化学气相沉积法、电子柬蒸发法。