长波长软X射线多层膜的设计与制备

“长波长软X射线多层膜的设计与制备”这篇论文介绍了用离子束溅射法制备长波长软X射线多层膜的研究工作,并报道了一种新的材料组合C/Si用于28.4nm(43. 65eV)和30.4nm(40.78 eV)波段的多层膜反射镜,并且用离子束溅射装置制备了正入 射条件下的C/Si多层膜反射镜.同时,用软X射线反射计测量了样品的反射率,从实验结果看出,制备的多层膜样品在28.4nm和30.4nm波段附近的实测正入射反射率分别达到11.4%和14.3%,实验指标达到了国内领先水平,并接近了国际水平.     

Si间隔层对Al(1wt.%Si)/Zr极紫外多层膜热稳定的作用研究

为了提升Al/Zr多层膜的热稳定性,采用直流磁控溅射方法制备了18个带有不同厚度Si间隔层的Al(1 wt.%Si)/Zr多层膜,并将这些样品分别进行了不同温度(100~500 ℃)的真空退火,退火时间为1 h.利用X射线掠入射反射(GIXR)和X射线衍射(XRD)的方法来研究Si间隔层对Al/Zr多层膜热稳定性的作用.GIXR测量结果表明:随着Si间隔层厚度的增大,Al膜层的粗糙度减小,而Zr膜层的粗糙度增大;XRD测量结果表明:Al和Zr膜层粗糙度的变化是由于退火后膜层中晶粒尺寸不同造成的.相比于没有Si间隔层的Al/Zr多层膜,引入厚度为0.6 nm的Si间隔层可以有效提升Al/Zr多层膜的热稳定性.     

软X射线多层膜反射镜界面粗糙度的一种估算方法

介绍了描述单个非理想粗糙界面散射的D .G .Stearns法 ,它适用于软X射线短波段区域。将这种方法应用到多层膜结构 ,并采用它的数学模型来描述软X射线短波段区域 (1～ 10nm)多层膜界面粗糙度。在此理论下 ,对波长为 4.77nm的Co/C多层膜反射镜界面粗糙度进行了分析 ,估算出该多层镜界面间均方根粗糙度为 0 7nm。     

软X射线多层膜反射镜界面粗糙度的一种估算方法

介绍了D.G.Sterns的散射方法,用它来描述单个非理想粗糙界面的散射,它适用于软X射线短波段区域.将这种方法应用到多层膜结构,并采用D.G.Sterns方法的数学模型来描述软X射线短波段区域(1～10 nm)多层膜界面粗糙度.在这个理论的框架下,对我们所研制的波长为4.77 nm的Co/C多层膜反射镜界面粗糙度进行分析,估算出该多层镜界面间均方根粗糙度为0.7 nm.粗糙度估算结果与小角X射线衍射的测定结果相一致.(PE13)     

磁控溅射不同厚度铝薄膜的微结构及其表面形貌

用直流磁控溅射法在室温的Si(100)基底上制备了21～55 nm范围内不同厚度的铝膜,并用X射线衍射和扫描电镜对薄膜的结构和表面形貌进行了表征.分析结果表明:制备的铝薄膜呈多晶状态,晶粒择优取向为(111),随着膜厚的增加,Al(100)衍射峰宽变窄,薄膜的平均晶粒尺寸逐渐增大,晶面间距逐渐减小,薄膜中的残余应力减小.膜厚为55 nm时,Al膜均匀致密.     

制备软X光多层膜的转速控厚法

本文提出了一种新的监控软X光多层膜膜厚的方法——转速控厚法,利用这种方法镀制的设计周期厚度分别为8.4和10nm,周期数达50对和30对的W/C多层膜,经小角X光衍射测试,结果表明周期厚度随机误差在0.1nm左右。     

常用间隔层材料软X射线多层膜的设计

为了研究常用间隔层材料的软X射线多层膜的材料设计,利用Lawrence-Livermore国家实验室提供的软X射线多层膜设计程序进行模拟计算,得到了软X射线波段内的具有高反射率的膜系。结果表明,Mo在相当大的波段范围内具有良好的光学特性;除了在12.44nm是首选膜系外(除4.36nm外),其它波长都有较高的反射率;U作为吸收层材料,在相当大的波段范围内,与其它间隔层材料配对的多层膜也具有较高的反射率。这对多层膜膜系的材料选择有一定的指导意义。     

氮掺杂SiC厚膜的制备及其热电特性

以Si C超细粉为原料,采用热等离子体PVD(TPPVD)法快速制备了Si C膜,最大沉积速度达到1 38nm /s.为了降低Si C膜的电阻率,提高其热电性能,采用向等离子体中通入N2 的方法对Si C膜进行了掺杂.用扫描电子显微镜、X射线衍射和X射线光电子谱对薄膜的形貌和结构进行了观察和分析.实验测定了Si C膜掺杂前后的热电性能并与Si C烧结体的结果进行比较.实验结果表明:向等离子体中导入N2 是对Si C膜进行掺杂的有效方法,但同时也显著影响Si C膜的形貌、成分和沉积速度.未进行氮掺杂和经过氮掺杂后的Si C薄膜的(S2 /ρ)值在973K时分别达到1 6 0 μW/(m·K2 )和1 0 0 0     

聚焦离子束切割法制备多层膜X射线波带片

X射线波带片是X射线显微成像系统中用于聚焦及成像的核心元件,提高波带片性能参数,更利于X射线显微成像技术的广泛应用。选择可精确控制厚度的原子层沉积(ALD)法结合聚焦离子束(FIB)切割法制备出大高宽比X射线波带片结构,即用原子层沉积法在光滑的钨丝表面交替沉积Al2O3/HfO2多层膜,其总层数为360,最外层膜宽度为10 nm。聚焦离子束的加速电压设定为30 kV,先利用束流为1 000 pA的离子束流将Al2O3/HfO2多层膜切割成设计厚度的薄片,再利用束流为350 pA的离子束流对切割的截面进行抛光,最后得到厚度为50μm、最外层膜宽度为10 nm的大高宽比X射线波带片结构。     

μc-Si∶H/a-Si∶H多层膜的周期性结构和量子尺寸效应

利用射频辉光放电法 ,通过周期性交替切换两种耦合电极的方式 ,制备了 μc- Si∶ H/a- Si∶ H多层膜 .低角度X射线衍射 (L AXRD)测试表明 ,这种多层膜具有良好的周期性结构 .观察了上述多层膜的光学性质及电导率与温度的关系 ,发现其吸收边随着 a- Si∶ H层的减薄而蓝移 ,低温下的电导激活能 Ea 随着 a- Si∶ H层的减薄而减小 .     

SiC/Mg multilayer reflective mirror for He-Ⅱ radiation at 30.4 nm and its thermal stability

In applications of solar physics, extreme ultraviolet imaging of solar corona by selecting the HeⅡ (λ = 30.4 nm) emission line requires high reflectivity multilayer mirrors. Some material combinations were studied to design the mirrors working at a wavelength of 30.4 nm, including SiC/Mg, B4C/Mg, C/Mg, C/Al, Mo/ Si, B4C/Si, SiC/Si, C/Si, and Sc/Si. Based on optimization of the largest reflectivity and the narrowest width for the multilayer mirror, a SiC/Mg material combination was selected as the mirror and fabricated by a magnetron sputtering system. The layer thicknesses of the SiC/Mg multilayer were measured by an X-ray diffractometer. Reflectivities were then measured on beamline U27 at the National Synchrotron Radiation Laboratory (NSRL) in Hefei, China. At a wavelength of 30.4 nm, the measured reflectivity is as high as 38.0%. Furthermore, a series of annealing experiments were performed to investigate the thermal stability of the SiC/Mg multilayer.     

Development of Multilayer Optics for the EUV, Soft X-ray and X-ray Regions in Tongji University

1 Introduction The EUV and X- ray optics has been regarded as one of the important fields in modern optics, having many promising applications in next generation lithography system, astronomical telescope, spectroscopy, plasma diagnostics and X- ray laser. However, in the EUV and X- ray regions, the nature of the complex optical con- stants of all materials makes the realization of the ideal optical elements like ones working in visible region im-possible. The development of EUV and X- ra…     

Near ultraviolet optically pumped vertical cavity laser

Optically pumped near ultraviolet vertical cavity laser operation (VCSEL) has been obtained under quasi-continuous wave conditions at room temperature near 383 nm from shallow InGaN/GaN multiple quantum wells (MQWs). Low loss optical resonators were fabricated by using in-situ grown (Al,Ga)N distributed Bragg reflectors that featured strain engineering design for high optical morphology, in combination with low-loss dielectric multilayer mirrors     

Si/C60多层膜一维光子晶体的光学特性

The feasibility of using Si/C60 multilayer films as one-dimensional （1D） photonic band gap crystals was investigated by theoretical calculations using a transfer matrix method （TMM）. The response has been studied both within and out of the periodic plane of Si/C60 multilayers. It is found that Si/C60 multilayer films show incomplete photonic band gap （PBG） behavior in the visible frequency range. The fabricated Si/C60 multilayers with two pairs of 70 nm C60 and 30 nm Si layers exhibit a PBG at central wavelength of about 600 nm, and the highest re？ectivity can reach 99%. As a consequence, this photonic crystal may be important for fabricating a photonic crystal with an incomplete band gap in the visible frequency range.     

Study on ta diffusion barrier in Al/Si system

The property of Ta as a diffusion barrier is studied for Al/Ta/Si structure. Interfacial reactions of Al(180 nm)/Ta(130 nm)/Si and Al(180 nm)/Ta(24 nm)/Si, in the temperature range 450∼600°C for 30 min, have been investigated. In Al/Ta(130 nm)/Si system, which is Ta-excess case, Al₃Ta is formed at 500°C. At 575°C, TaSi₂ is formed at the interface of Ta Si. At 600°C, after Al₃Ta decomposes at the interface of Al₃Ta TaSi₂, free Ta is bonded to TaSi₂ with the supply of Si from Si substrate and free Al diffuses through TaSi₂, resulting in Al spiking. In Al/Ta(24 nm)/Si system, which is Al-excess case, Al₃Ta is formed at 500°C. At the same temperature of 500°C, after Al₃Ta decomposes at the interface of Al₃Ta/Si, free Ta reacts with Si to form TaSi₂ and free Al diffuses to Si substrate, resulting in Al spiking. The results of interfacial reactions can be understood from the calculated Al-Si-Ta ternary phase diagram. It can be concluded that the reaction at Al/Ta should be suppressed to improve the performance of Ta diffusion barrier in Al/Si system.     

45°角入射的13.1nm软X射线多层膜的研制

报道了对４５°入射角高反的１３．１ｎｍ软Ｘ射线多层膜反射镜的研制情况。利用在星光装置中进行的软Ｘ射线激光等离子体实验测量多层膜反射率的方法，获得了２６．２％的实测反射率，该反射率已达到理论反射率的７０％。     

Temperature dependence of the properties of DBR mirrors used insurface normal optoelectronic devices

The variation in the center wavelength of distributed Bragg reflectors used in optoelectronic devices, such as surface emitting lasers and Fabry-Perot modulators, is measured as the temperature of the mirrors changes over the range 25°C to 105°C. An analytic expression for the shift in center wavelength with temperature is presented. The mirrors measured are made of InP/InGaAsP (λ_gap=1.15 μm), GaAs/AlAs, and Si/SiN_x. The linear shifts in center wavelength are 0.110±0.003 nm/°C, 0.087±0.003 nm/°C, and 0.067±0.007 nm/°C for the InP/InGaAsP, GaAs/AlAs, and Si/SiN mirrors, respectively. Based on these data, the change in penetration depth with temperature is calculated     

高反射率193 nm Al2O3/MgF2反射膜的实验研究

用电子束热蒸发方法在熔融石英基底上沉积了Al2O3和MgF2两种材料的单层膜，研究了两种材料的光学特性，采用光度法计算并给出了薄膜材料在180～230nm的折射率n／和消光系数k的色散曲线。以两种材料作为高低折射率材料组合，采用1／4波长规整膜系设计并镀制了193nm的高反射膜，反射膜在退火后的反射率在193nm达到96％以上。结果表明在一定工艺条件下Al2O3和MgF2两种材料能够在193nm获得较好的光学性能，适用于高反射膜的制备。