极紫外与短波长软X射线多层膜的研制
文献类型：学位论文
| 作者 | 秦俊岭 |
| 学位类别 | 博士 |
| 答辩日期 | 2007 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 邵建达 |
| 关键词 | 软X射线 多层膜 反射率 模拟研究 Mo/Si |
| 其他题名 | Fabrication of Extreme Ultraviolet and Short Wavelength Soft X-ray Multilayer |
| 中文摘要 | 在软X射线波段（0.2-50nm），任何材料的折射率均接近于1，而且吸收很大，无法组成透射式光学系统，同时单层膜反射镜对近正入射软X射线反射率几乎为零，因此正入射软X射线成像系统只能由镀有软X射线多层膜的反射镜构成。 软X 射线多层膜的膜层非常薄，一般仅几个纳米，在制备超薄多层膜时很难制备出膜层连续的多层膜结构。本文用一个简单的不连续多层膜模型模拟研究了多层膜不连续度对其软X射线光学性能的影响，证明随着不连续度的增加，软X射线多层膜的峰值反射率下降。超薄多层膜不仅很难制备出连续的膜层，而且膜层间的扩散也比较严重，为了克服以上两个制备多层膜的难点，本文提出了一种周期性梯度折射率软X射线多层膜的设计方法。分别采用折射率正弦周期性变化模型和折射率直线周期性变化模型研究了软X射线多层膜的反射率，结果表明，用正弦模型设计的多层膜的软X射线反射率达到理想多层膜设计反射率的85％以上。这种折射率周期性梯度变化的多层膜的设计方法对软X射线多层膜的设计具有一定意义。为了防止软X射线多层膜的界面扩散，还可以在两个膜层间增加第三种材料膜层来屏障界面扩散，文中用四层结构模型模拟了Mo/Si多层膜的软X射线反射率，详细的研究了扩散屏障层dMo-on-Si和dSi-on-Mo对Mo/Si多层膜软X射线反射率的影响。研究发现，扩散屏障层并不总是损害Mo/Si多层膜的光学性能，通过合理设计dMo-on-Si和dSi-on-Mo厚度，增加dMo-on-Si与dSi-on-Mo的比值，它也能提高多层膜的软X射线反射率。 详细研究了膜层数对Mo/Si多层膜的表界面粗糙度和软X射线反射率的影响。随着膜层数的增加，Mo/Si多层膜的表面粗糙度先增加后减小，界面粗糙度一直增加。多层膜的软X射线反射率主要由膜层数和界面粗糙度决定，随着膜层数增加，反射率先增加后减小。 Mo靶溅射功率对Mo/Si多层膜的微结构和光学性能也有很大影响。随Mo靶溅射功率增大，多层膜的表面粗糙度增加，Mo膜层结晶，Mo/Si多层膜的软X射线反射率先增加后减小。Mo靶溅射功率具有一个最佳值使Mo/Si多层膜的软X射线反射率达到最大。 用AES和XPS简单分析了本实验室所用磁控溅射系统制备的Mo/Si多层膜的组分。表明Mo/Si多层膜含有原子百分含量20％左右的N和O，多层膜中含有Si氧化物和Mo氧化物。 本文最后列出了中心波长13.5nm和13.9nmMo/Si多层膜的制备结果，也给出了中心波长4.4nm的Fe/C和Co/C多层膜的初步结果。 |
| 英文摘要 | In the soft X-ray wavelength range from 0.2~50nm, not only do refractive index of any materials be close to 1, but also their absorption are very much, which make the transmitted light system impossible. Even soft X-ray reflectivity of single layer thin film mirror is zero, hence normal incidence soft X-ray optical system is only consisted of soft X-ray multilayer mirrors. Soft X-ray multilayer is very thin and only several nanometers. Single continuous film layer in multilayer is hardly fabricated. This paper use a simple discontinuous model simulate the influence of discontinuous degree on soft X-ray reflectivity of multilayer. It prove that the peak reflectivity reduce as increasing discontinuous degree. Ultra-thin film multilayer has not only discontinuous film layer but also inter-diffusion. In order to deal with those two difficulties, this paper put forward a new design method of periodic graded-index multilayer. A line model and a cosine model are respectively used to simulate soft X-ray reflectivity of periodic graded-index multilayer. The simulations show that periodic graded-index multilayer with cosine model have a higher reflectivity. it is significative for design of ultra thin multilayer. With the aim of preventing interface diffusion, it can add a third material into multilayer, A four-layer model was used to simulate soft X-ray reflectivity of Mo/Si multilayer at a given wavelength. By simulation, the influence of inter-diffusion barrier dMo-on-Si and dSi-on-Mo on the soft X-ray reflectivity of Mo/Si multilayer has been detailedly studied. The simulation study shows that inter-diffusion barrier is not always disadvantageous to optical capability of Mo/Si multilayer, through designing a right thickness of dMo-on-Si and dSi-on-Mo, increasing the thickness ratio of dMo-on-Si and dSi-on-Mo, it can also improve soft X-ray reflectivity of multilayer. Influence of layer number on interface roughness, surface roughness and soft X-ray reflectivity of Mo/Si multilayer are studied. The surface roughness and peak reflectivity of the Mo/Si multilayer increase firstly and then decrease as number of layers. The interface roughness of the Mo/Si multilayer increase as number of layers. Number of layer and interface roughness have the main effect on reflectivity of multilayer, effect of surface roughness is small. Sputtering power of Mo target have a strong effect on microstructure and optical performance of Mo/Si multilayer. As sputtering power of Mo target increasing, surface roughness of Mo/Si film was increasing, characteristic diffraction peak of Mo species became stronger and stronger, furthermore, soft X-ray peak reflectivity of Mo/Si Multilayer increased first and then reduced. There is a optimum value of sputtering power of Mo target to make Mo/Si multilayer the maximum reflectivity. Using AES and XPS we analyze the component of Mo/Si multilayer which is prepared by our magnetron sputtering system. It shows that Mo/Si multilayer contain nitrogen and oxygen 20% atomic percent, and also contain silicon oxide and molybdenum oxide. There list some results about Mo/Si multilayer at wavelength 13.5nm and 13.9nm. There also list some results about Fe/C and Co/C multilayer at wavelength 4.4nm. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15489]  |
| 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 | 秦俊岭. 极紫外与短波长软X射线多层膜的研制[D]. 中国科学院上海光学精密机械研究所. 2007. |
入库方式： OAI收割
来源：上海光学精密机械研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。