掺氮氧化钒薄膜的椭偏光谱表征

利用反应溅射法,在Si(100)衬底上沉积了掺N氧化钒薄膜.借用SE850椭偏仪对薄膜进行了近红外波段(1300-2300 nm)的光谱测量,运用Tauc-Lorentz模型对薄膜的椭偏光谱数据进行了拟合,并计算了薄膜的光学参数(n,k)和厚度.结果表明:随着掺N量的增加,氧化钒薄膜的光学参数(n,k)随之增加,而其沉...     

直流磁过滤电弧沉积氮化铝薄膜的研究

利用直流电弧技术在硅基片上制备氮化铝薄膜,研究了薄膜的折射率、消光系数、透过率和沉积速率.薄膜的光学折射率、消光系数、厚度通过椭偏法测试并拟合得到;薄膜的透过率谱通过傅里叶变换红外光谱仪测试,薄膜的沉积速率通过厚度的相应时间计算得到;利用柯希模型来拟合测试得到可见区光学常数,外推得到薄膜在整个近红外、中远红外的光学常数.结果表明:薄膜的折射率随工艺参数的不同有较大的变化范围,并且薄膜在较宽的光谱范围内消光系数为零;薄膜的沉积速率达到85 nm-min-1,单面镀制氮化铝薄膜的硅样片的峰值透过滤达到了69.2%.     

多步旋涂CsPbBr3薄膜复光学常数的椭偏光谱研究

为了研究多步旋涂法制备的CsPbBr₃薄膜的光学常数，以溴化铅和溴化铯为原料，采用多步旋涂法在硅和FTO衬底上制得CsPbBr₃薄膜。利用光弹调制式椭偏光谱仪对硅衬底上的薄膜进行了椭偏光谱分析，使用Tanguy和Tauc-Lorentz 3组合模型对变角度的椭偏光谱进行参数拟合，得到了薄膜光学常数在1.00 eV～5.00 eV范围内的色散关系，并利用荧光发射光谱、吸收谱验证椭偏拟合结果。结果表明，多步旋涂法制备的CsPbBr₃薄膜的光学常数与其它方法相比具有一定的差异性，其中折射率可能与薄膜表面粗糙度呈负相关；椭偏拟合所得带隙为2.3 eV,验证了荧光光谱、吸收谱的计算结果。该研究为多步旋涂法制备的CsPbBr₃薄膜椭偏光谱拟合分析提供了参考。     

磁控溅射制备的氧化钒的椭偏光谱分析

采用直流反应磁控溅射工艺,在不同的沉积时间条件下(5～100min)制备了以单晶硅为衬底的氧化钒薄膜,用扫描电镜分析了薄膜结构的断面形貌.对氧化钒薄膜建立了椭偏色散模型[1],运用经典振子模型在椭偏仪上拟合并计算薄膜的透射光谱得到理想的拟合效果,发现在300～450nm内其折射率随波长的增加而增大,而在450～700nm内逐渐减小,632.8nm波长下磁控溅射制备的氧化钒薄膜折射率在2.2～2.5.初始沉积薄膜折射率较大,而随着沉积时间的增加,不同厚度的薄膜折射率从2.43到2.24呈现略微减小的趋势.用拟合得到的厚度值来计算出沉积速率,发现沉积速率也逐渐变小.     

玻璃基底和表面粗糙度在氮化硅薄膜椭偏测量中的影响

在光谱椭偏测量中,玻璃基底的背反射会给测量结果造成较大影响。针对平板显示器件玻璃基底表面氮化硅镀膜进行了椭偏测量和模型计算。采用相干背反射模型“空气基底空气”计算并拟合得到与厂商数据符合较好的玻璃基底折射率。对氮化硅薄膜采用Tauc Lorentz色散模型进行了分析拟合,讨论了薄膜与基底界面层、表面粗糙度对光学常数及模型拟合的影响,表明在薄膜与基底间晶格失配的情况下,界面层的引入对改善拟合度是必要的。给出了薄膜体系的光学常数、薄膜结构的分析结果。     

唯一性检测在椭圆偏振光谱薄膜拟合中的应用（英文）

利用椭圆偏振光谱进行薄膜样品的测量数据分析拟合时,薄膜厚度与介电常数通常具有一定的关联性.不同色散模型的选取也会对拟合结果产生明显的影响,引起较大误差.介绍了唯一性检测在椭偏拟合中的实现方法.并以二氧化钛样品为例,利用唯一性检测对比了不同色散模型、不同厚度、不同测量波段、不同入射角度时的唯一性检测结果.结果表明,唯一性检测能够有效标定出椭偏测量和拟合过程中所产生的误差,同时能够对不同色散模型进行量化对比,提升拟合精度.     

酞菁氧钛薄膜光学常数的测量研究

使用M-2000UI型宽光谱可变入射角椭偏仪,对在单晶硅片上真空蒸镀的酞菁氧钛(TiOPc)薄膜的光学性质进行了研究.在248～1650 nm(0.75～5 ev)的范围内分别使用柯西模型、逐点拟合模型、洛伦兹模型和高斯模型对测得的椭偏光谱进行拟合分析,获得了TiOPc薄膜的折射率、消光系数和复介电常数.通过比较,我们发现高斯模型拟合的均方差较小,拟合数据和测试数据重合度好,而且拟合得到的光学常数的图线光滑连续,因此认为高斯模型最适用于描述TiOPc薄膜的光学性质.由高斯模型拟合所得的消光系数推出了TiOPc薄膜的吸收谱,结果发现TiOPc薄膜存紫外可见近红外区有一系列的吸收峰,分析了其电子结构及吸收谱成因,并由吸收谱推算了其光学禁带宽度.     

气体压强对非晶硅薄膜光学特性的影响

采用RF-PECVD工艺在20～100 Pa范围内改变a-Si:H薄膜沉积工作气体压强.傅立叶红外光谱仪(FTIR)测试KBr衬底上的薄膜红外光谱峰随工作气体压强的变化情况,结合红外光谱峰的理论分析确定薄膜中氢含量随工作气体压强变化规律.光谱式椭偏仪中用Forouhi Bloomer(FB) 模型拟合得到薄膜的折射率(n),消光系数(k),厚度及光学禁带Eg,并用扫描电镜(SEM)断面分析对椭偏仪测试结果的准确性进行验证.根据Tauc公式推出薄膜的光学禁带宽Eg和截止波长,并和FB模型得到结果进行了比较,Eg(FB)和Eg(Tauc)的差值在11 meV内.原子力显微镜(AFM)和X射线衍射(XRD)表征了工作气体压强对a-Si:H薄膜微结构的影响.     

a-SiCdTe∶H薄膜做液晶光阀光敏层的光学特性研究

采用射频磁控溅射法制备了用于液晶光阀光敏层的a-Si1-x(CdTe)x∶H薄膜.研究了CdTe含量对氢化非晶硅薄膜光学性能的影响.采用扫描电镜(SEM)、X光电子能谱(XPS)、椭偏仪等测试手段对薄膜的表面形貌、成分和光学性能进行了表征.结果表明,薄膜的折射率和吸收系数均随x值的增大而增大;而光学带隙E.pt随x值的增大从2.01 eV降到1.75 eV.薄膜在可见光范围内透过率随着x值的增大而有所降低,且吸收边发生红移.     

类金刚石薄膜光学参数反演的改进遗传算法

椭偏法测试薄膜不能直接得到薄膜的光学参数,需进行数值反演算法近似求解.采用遗传算法,借鉴竞争选择、小生境和适应值调节思想,对选择算子、变异算子、交叉算子三个重要箅子进行了适当改进,改进后算法有效防止了"早熟"现象.并搜索到了全局最优,降低了操作者对拟合模型设定初值的要求.在实践上.通过3种拟合方式的结果对比,得到了可靠...     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.