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题名	基于表面等离子体共振的探针诱导光存储材料研究
作者	李小刚
学位类别	硕士
答辩日期	2008
授予单位	中国科学院上海光学精密机械研究所
导师	王阳
关键词	表面等离子体共振，近场记录，AgOx薄膜，NiOx薄膜，探针诱导记录
其他题名	Study on probe-induced optical recording materials with surface plasma resonance
中文摘要	随着生化和信息等领域研究的不断深入，社会需求的不断提高，一些高新技术应运而生，其中表面等离子体共振技术和近场光刻技术的应用备受关注。将表面等离子体共振技术与近场光刻技术相结合，我们提出了基于表面等离子体共振的探针诱导光存储的新概念。本论文重点开展了基于表面等离子体共振的探针诱导光存储材料的研究，包括相关理论计算、材料选择、薄膜制备、材料光学和结构特性以及探针记录实验等。 论文首先简介了近场光学理论和表面等离子体激发理论，综述了采用原子力探针作为光存储执行机构的功能薄膜材料的研究现状和探针存储研究进展和发展趋势，提出了本文的主要研究内容。 理论计算研究了基于棱镜耦合的薄膜表面等离子体共振的性质，分析了金属层、介质层、记录层和棱镜的厚度及折射率对表面等离子体共振（SPR）角谱的影响。金属薄膜的折射率是影响共振半峰宽度和共振深度的主要因素，计算表明存在一个最佳的金属层厚度，使得共振深度最大，反射系数最小；介质层和记录层的折射率和厚度的变化均会影响共振角的大小和共振峰半峰宽的变化。棱镜与介质的折射率差别越大，SPR的灵敏度就会越高，因此应该选取具有较大折射率的棱镜作为入射介质。以此为依据，我们分别选定了Ag、SiO2作为金属层和介质层材料；对于记录层，考虑折射率匹配及记录特性，我们尝试了AgOx、NiOx两种材料；至于棱镜和衬底，我们选择的玻璃材料为ZF6。实验过程所采用的样品主要包括镀在ZF6玻璃片上的单层结构的Ag膜、双层结构的Ag/AgOx 或Ag/NiOx和三层结构的Ag/SiO2/AgOx或Ag/SiO2/NiOx。 对单层的Ag、SiO2、AgOx和NiOx薄膜，我们优化薄膜的制备工艺，在膜层小于50 nm厚度时获得小于2 nm的表面粗糙度。两种非化学剂量比氧化物AgOx和NiOx薄膜的光学常数，对溅射气氛中的氧分压、溅射功率、工作气压等因素非常敏感，可以通过控制溅射参数来适当的调节所需的薄膜光学常数。采用光谱仪、XRD、XPS、退火、激光初始化等手段对AgOx和NiOx薄膜在不同退火（包括激光退火）条件下的光学和结构特性进行深入研究，结果表明，这两种氧化物在热和光热的作用下都会发生不同程度的分解反应，同时引起薄膜价态和成分的变化。 测试了不同结构膜层的实际共振角，实施了基于表面等离子体共振的探针诱导记录实验，研究了激光功率、脉宽、膜层结构、入射角、聚焦程度、探针电压等对记录点尺寸的影响。单层、双层、三层薄膜SPR谱的实验测试值与理论计算值的差别逐渐加大，而三层薄膜的表面等离子体共振现象十分微弱，这可能是由于Ag薄膜表面的单个颗粒在激光照射条件下会发生局域表面等离子体共振效应以及实际制备薄膜的精确控制偏离，而且随着膜层的增多，偏离越来越大。基于表面等离子体共振的探针诱导记录实验中，对于单层薄膜，记录点随着曝光时间和激光功率的增加直径略有增大，而记录点深度则会随着曝光时间的增大不断增加；金属层厚度小于50 nm时，尽管表面等离子体共振效果减弱，但透射光强可以进行弥补场能量；提高激光聚焦程度，可以提高激光照射区薄膜表面的光功率密度和原子力探针针尖处的能量利用效率，进而能够获得更好的记录点。对于双层薄膜，短的曝光时间可以形成凹坑记录点而长的曝光时间形成凸起的记录点，在同样的记录条件下AgOx薄膜所需要的曝光记录时间远小于NiOx薄膜。对于三层薄膜，Ag/SiO2/AgOx膜层表面可形成记录点凹坑，而Ag/SiO2/NiOx膜层薄膜表面没有任何反应，这是由于NiOx薄膜的光热反应活性远不如AgOx薄膜，它对激光功率的变化并不敏感，对于曝光时间也仅仅是累积的热效应。探针诱导记录实验中记录点凹坑尺寸一般平均在100-140 nm、深度7-20 nm，最小直径可达80 nm。
英文摘要	With the development of bio-chemistry and information technology, and the improvement of social request, some new technologies emerge to meet the demands. Application of surface plasma resonance technology and near-field lithography technology attract lots of attentions. In this thesis, the conception of probe-induced optical recording based on surface plasma resonance is proposed. Theoretical simulation, material selection, film preparation, optical ang structure properties and recording characteristics were studied. At first, the theories of near-field optics and surface plasma excitation were introduced. The recent research progress of SPP-related functional films and probe-induced recording were reviewed. Then the research subjects of this thesis are proposed based on it. Theoretical calculation of the prism coupled surface plasma resonance was studied. The effects of refractive index and thickness of the metal layer, the dielectric layer, recording layer and the prism on SPR spectrum were analyzed. The refractive index of metal effects mainly resonance depth and the half peak breadth. There is an optimum metal thickness with the largest resonance depth and the smallest reflection coefficient. The refractive index and thickness of dielectric layer and recording layer impact resonance angle and the half peak breadth. The greater difference between the refractive index of dielectric layer and prism, the higher sensitivity of SPR will be obtained. So the prism with high refractive index was selected. We selected Ag and SiO2 as the materials of the metal and dielectric layer respectively. Considering refractive index matching and recording characteristic, we used AgOx and NiOx films as the recording layer. ZF6 glass was chosen as prism and substrate materials. Single-layer Ag films and multilayer films with the structure of Ag/AgOx, Ag/NiOx, Ag/SiO2/AgOx, Ag/SiO2/NiOx on ZF6 glass substrate were used in our experiments. We optimized the preparation parameters of Ag, SiO2, AgOx and NiOx single layers. The measured surface roughness of a 50 nm thick film can be less than 2 nm.. Optical constant of AgOx and NiOx films are sensitive to preparation parameters such as pressure of oxygen, sputtering power, working pressure, etc. We can control their optical constants by changing sputtering parameters. The optical and rtructural properties of AgOx and NiOx films under different annealing conditions (including laser initialization) had been studied by spectrometer, XRD and XPS. Heat and photothermal induced decomposition reaction took place in these two oxides, causing the changes of value configuration and composition. Actual resonance angles of different films were tested. And probe-induced recording experiments based on surface plasma resonance were carried out. The difference between measured value and theoretical calculation for single-layer, two-layer and three-layer films gets larger and larger and surface plasma resonance becomes weaker and weaker. It may be caused by local surface plasma resonance effect of Ag nanoparticles and the deviation of film homogeneity arised from preparation process. The more the layer number, the larger deviation will be obtained. The diameters of recording marks increase a little with exposure time and laser power while the depth increase with exposure time constantly for single Ag films. For the metal thickness smaller than 50 nm, though the surface plasma resonance effect is weakened, the transmission gets stronger and compensates the weakened part. By improving laser focuscharacteristics, the power density of recording area and the energy utilization efficiency of tip will ba increased, and then better recording marks can be obtained. It can form recording pits at a short exposure time while recording bubbles at a long exposure time. The exposure time to forming marks of AgOx films is shorter than that on NiOx films for double-layered structure. Recording marks can be formed on Ag/SiO2/AgOx structure while no marks can be formed on Ag/SiO2/NiOx structure. It is mainly because that the photothermal activity of NiOx films is not so good as that of AgOx films. It is not so sensitive to the laser power, and longer exposure time just accumulates more heat. The average diameter of recording pits is about 100-140 nm with depth of 7-20 nm. The minimum size can be 80 nm.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/16386]
专题	上海光学精密机械研究所_学位论文
推荐引用方式 GB/T 7714	李小刚. 基于表面等离子体共振的探针诱导光存储材料研究[D]. 中国科学院上海光学精密机械研究所. 2008.

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