Surface State Variation during Scanning in a Low-Voltage SEM and Its Effect on of Relief Structure Sizes

Physics of the Solid State - The variation of low-energy slow secondary electron emission from the surface of relief structures (bumps) during their prolonged scanning in a low-voltage scanning...     

波长扫描法布里-珀罗干涉仪的优化设计

分析了可用于绝对距离测量的波长扫描法布里－珀罗干涉仪腔内多光束干涉对输出信号的影响, 及由此产生的相位测量误差。研究表明, 通过选择合适的腔端面反射率和参考腔长度可以减小相位测量误差。优化选择的腔面反射率为０．１０～０．１５, 参考腔长为０．９５ ｍ ｍ , 在１ ｍ ｍ 范围内系统可达到０．０５ μｍ 的测距精度。     

Effect of the State of the Cathode Surface on its Photoemission Properties

The results of experimental investigation of the effect of the state of the cathode surface on its photoemission properties are presented. It is found that the low-pressure glow discharge treatment of the copper cathode surface in the air results both in a substantial shift of the photoeffect threshold to the long-wave region of a spectrum and in a change of the quantum photoemission yield.     

The Effect of Wettability of Nickel Mold Insert on the Surface Quality of Molded Microlenses

In micromolding of microlens array, it is important to prepare a mold insert of superb quality, which contains the micro-cavity of lens shape, because the geometrical quality of the mold insert defines the final quality of the molded micro-optics. In the present study, the electroforming process was used to make the metallic micro-mold insert for micro-molding of microlens array. The wettability property of the fabricated mold isnert was examined by measuring the contact angle of the polymer in the pliable state on the mold insert. Microlenses were compression-molded with the fabricated mold insert. The effects of the molding temperature and wettability property on the replication quality of the molded lenses were analyzed experimentally.     

表面偶极子对扫描电子显微镜共振电子注入的影响

用共振电子注入法和第一性原理计算研究了硒(Se)单原子在Si(111)-7×7表面的吸附. 理论结果表明由于不同的电负性,表面Si原子会向吸附的Se原子发生电子转移,从而导致一个0.61 eV的表面偶极子形成. 该表面偶极子改变了Si表面的有效隧道能垒同时导致在样品和扫描电子显微镜针尖之间真空间隙中共振态能级的移动. 并且0.61 eV的表面偶极子会引起共振电子注入偏压向高电位移动0.45 V.     

A New Step in the Optimization of the Chambadal Model of the Carnot Engine

This paper presents a new step in the optimization of the Chambadal model of the Carnot engine. It allows a sequential optimization of a model with internal irreversibilities. The optimization is performed successively with respect to various objectives (e.g., energy, efficiency, or power when introducing the duration of the cycle). New complementary results are reported, generalizing those recently published in the literature. In addition, the new concept of entropy production action is proposed. This concept induces new optimums concerning energy and power in the presence of internal irreversibilities inversely proportional to the cycle or transformation durations. This promising approach is related to applications but also to fundamental aspects.     

Magnification Effects in Scanning Tunneling Microscopy: the Role of Surface Radicals

Journal of Experimental and Theoretical Physics - Scanning tunneling microscopy (STM) is a fundamental tool for determination of the surface atomic structure. However, the interpretation of high...     

Scanning Tunneling Microscopy of the Ytterbium Nanofilm Surface and Layers of Oxygen Molecules Adsorbed on It

Technical Physics - The surfaces of Yb–Si(111) and O–Yb–Si(111) structures (with a thickness of ytterbium nanofilms of 16 monolayers (6.08 nm)) have been investigated for the...     

光针扫描法检测光滑表面粗糙度

提出了一种用于光滑表面粗糙度测量的方法，利用两个标准参考面和两个偏振片实现对表面粗糙度的测量，通过两1／4波片克服光路可逆性的缺陷，给出了测量系统光路图，导出了该方法工作原理的数学表达式，并对该方法产生的测量不确定度进行了理论计算与计算机仿真，最后通过对一标准粗糙度样块进行测量，证明了该方案的可行性。结果表明实测值与样块厂家提供的标称值相符，并可实现0．2nm的测量精度。     

步进扫描投影光刻机剂量控制参量优化新算法研究

提出了一种以生产率、剂量精度与激光器使用成本三者最佳匹配为优化目标的步进扫描投影光刻机剂量控制参量优化新算法及其数学模型,通过将激光器重复频率作为可调参量并引入有效脉冲个数的概念,获得了有效剂量区间内任意给定剂量所应采取的优化策略并给出了剂量控制参量的具体计算方法。理论推导和模拟计算结果表明,新算法既保持了原算法在生产率和剂量精度优化方面的优势,又改进了原算法在激光器成本优化目标上的缺陷。随着准分子激光器及其剂量控制技术的进一步发展,新算法可望更能显示出其优越性并具有更广阔的应用前景。     

激光扫描实时共聚焦显微成像系统设计

共聚焦扫描显微镜已成为生物医学和材料科学领域研究中非常有价值的一种工具.本文给出了一种反射型激光扫描共聚焦显微成像系统的系统结构和具体设计.采用多面体转镜进行水平扫描,摆镜进行垂直扫描.利用商品透镜设计了光学扫描中继系统,采用光电倍增管作为激发出的荧光探测器,同时给出了数据采集和扫描同步控制系统的组成与设计.利用COD...     

激光扫描实时共聚焦显微成像系统设计

共聚焦扫描显微镜已成为生物医学和材料科学领域研究中非常有价值的一种工具.本文给出了一种反射型激光扫描共聚焦显微成像系统的系统结构和具体设计.采用多面体转镜进行水平扫描,摆镜进行垂直扫描.利用商品透镜设计了光学扫描中继系统,采用光电倍增管作为激发出的荧光探测器,同时给出了数据采集和扫描同步控制系统的组成与设计.利用CODE V优化光学扫描系统以获得尽可能小的扫描光斑尺寸和较大的视场,并综合考虑了采样频率、扫描速度和探测器对整个系统性能的影响,从而给出了该型共聚焦显微成像系统的相互匹配的设计参量.分析结果表明:共聚焦扫描系统设计合理可行|从光学扫描系统到PMT探测单元的各项技术指标得到优化,满足实时探测的要求|该系统具有适应性强,易升级,低成本的技术特点,同时可达到同类商品的技术性能.     

Effect of the Arsenic Concentration on the Characteristics of the Growth Step Echelon in GaAs Epitaxy

The effect of the arsenic concentration in the vapor phase on the growth step distribution over the surface of GaAs epitaxial layers grown in a chlorine-hydride vapor-transport system on substrates with 4° (111)A and (113)A orientations is studied. It is demonstrated that the average distance between steps in the echelon depends on the arsenic concentration and increases with it up to a certain constant value. It is assumed that this is connected with the change in the kink density at the steps.     

Fiber-optic Based Scanning Confocal Microscopic Interferometer for the Measurement of Surface Topography

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Fiber-optic Based Scanning Confocal Microscopic Interferometer for the Measurement of Surface Topography

A fiber-optic based scanning confocal microscopic interferometer with digital feedback is developed for the precise measurement of the surface topography on a large-scale object of complex shape with steep surface slopes. Theoretical analysis on interference formation demonstrates the confocal characteristic of the proposed interferometer along its measurement path. Experimental results confirm the spatial resolution of the measuring system to be within 1 μm and the measurement accuracy to be better than 5 nm.     

飞秒激光微细加工中光耦合器参数的数值模拟

用有限差分迭代求解光束传输方程,对1×2(Y型)耦合器和2×2(X型)耦合器分路的夹角大小对分路中光束分配比例的影响进行了模拟研究.模拟结果显示：耦合器夹角控制在一定的范围内,对分路中光束能量分配影响不大;2×2耦合器对分路夹角以及波导宽度的变化敏感.为飞秒激光加工光纤无源器件的可行性做了理论上的分析.     

Study of the Surface Processes in Vapor-Phase Epitaxial GaAs: Asymmetric Trapping of Atoms at the Step

Experimental proofs of asymmetric trapping of atoms at the growth step in vapor-phase epitaxy of gallium arsenide in the GaAs–AsCl₃–H₂ system are given. The data obtained confirm the important role of the surface diffusion mass transfer in the growth of epitaxial GaAs layers on vicinals in the neighborhood of (111)A. The effective diffusion length is estimated.     

用扫描近场光学显微镜技术研究金膜表面等离体子共振

表面等离体子波(SPW)可与入射光横磁波极化能量耦合并被共振激发,这种现象被称为表面等离体子共振现象(SPR)。主要利用扫描近场光学显微镜(SNOM)技术和表面等离体子共振现象技术相结合,来研究金膜表面等离体子共振。设计并建立了结构独特的新型Kretschmann型表面等离体子共振现象耦合装置,同时又设计了具有厚度梯度的表面等离体子的制备方法。在此基础上,测量了改变入射角条件下的表面等离体子共振曲线,测得该装置的等离体子共振角灵敏度为1°。并且对金膜表面进行表面等离体子共振条件下的扫描近场光学显微成像。实验结果表明,在共振时金膜表面的扫描成像比不共振时清晰,而且增加了很多细节。应用表面等离体子共振现象技术将可以明显提高扫描近场光学显微镜的信噪比、分辨力等性能。     

红外热成像系统中冷反射的分析和控制

介绍了红外成像系统中冷反射形成的原因。通过对实际的光学系统的近轴光路分析,分析了在红外扫描成像系统中容易出现冷反射的两种主要情形,描述了针对这两种主要的冷反射,在光学系统的设计中,所采取的抑制冷反射的措施。最后根据光学系统的设计实例,分析了镀膜对冷反射的影响,给出透镜镀制不同反射率的膜层时,该光学系统中冷反射的计算及分析数据。