可提高光刻分辨率的新技术

详细研究了离轴掩模的原理,将离轴照明(OAI)与相移掩模(PSM)技术结合起来,在掩模上同时实现两种功能,较大程度地提高了光刻分辨力.实验表明,在数值孔径 0.42,线曝光波长下,可将光刻分辨力从 0.8μm提高到 0.5μm.     

粒子场相移全息术

本文利用相移全息术记录的双曝光粒子场全息图,以改进再现图像的SNR、分辨率和对比度。并发展了这种技术的理论,讨论了相移的引入方法,给出了实验结果,与通常的同轴和离轴双曝光结果进行了比较。     

激光全场模态测量技术研究

详细阐述了电子散斑时间平均法振动测量技术的原理,通过对影响测量精度的诸因素进行理论和实验分析,提出通过应用连续相位扫描技术克服相移系统相移不准确所带来的误差.通过散斑平均技术的实施,消除散斑对测量精度的影响.在实验中得到了满意的测量结果.通过线性近似法,解决了振幅低于30nm的振动测量问题,从而使系统分辨率达到亚纳米级,测量精度达到纳米级.     

Mirau相移干涉法测量微透镜阵列面形

基于Mirau相移干涉法,在实验室环境下对微透镜阵列的微表面形貌进行了轮廓测量.实验使用He-Ne激光器作为光源,干涉成像系统由Mirau干涉物镜和其他光学元件组成.在实验中使用压电陶瓷执行器作为相移器,通过5步相移法计算待测表面形貌.实验结果表明,基于Mirau相移干涉法对微透镜阵列面形的测量,水平分辨率达到1.1 μm,垂直测量准确度达到6.33 nm,垂直测量范围为5 μm.对于微透镜阵列的面形测量,通过将微透镜阵列划分为若干微小区域以保证局部面形最大高度小于5 μm,然后辅以精密平移机构进行若干次5步相移法测量局部面形,再利用相位重建所得的数据进行拼接和3D轮廓重建,最终得到整个微透镜阵列的精确微表面形貌.     

基于相移技术的显微数字全息重构细胞相位

介绍了用显微镜物镜、压电陶瓷和CCD建立的一套测量细胞相位的显微数字全息光路,基于相移技术,给出了重构相位的理论分析,并用洋葱磷片叶细胞作为测试样品,完成了测量细胞相位的实验.结果表明：该系统可以完成细胞相位重构,系统分辨率不低于1 μm.     

脉冲跨周期调制连续导电模式Buck变换器低频波动现象研究

揭示了脉冲跨周期调制(pulse skipped modulation,PSM)电感电流连续导电模式(continuous conduction mode,CCM)Buck变换器中存在的低频波动现象,分析了PSM调制CCM Buck变换器的能量转换过程,阐述了低频波动的产生机理,给出了低频波动的判断条件.建立了PSM调制CCM Buck变换器的同步开关映射模型,基于该模型给出了电感电流与输出电压随输出电容等效串联电阻(equivalent series resistance,ESR)变化的分岔图,分析了ESR对低频波动的影响.为消除PSM调制CCM Buck中存在的低频波动,提出了电容电流脉冲跨周期调制(capacitor current pulse skipped modulation,CC-PSM)方法.研究结果表明:在ESR较小时,CC-PSM调制CCM Buck变换器消除了PSM调制CCM Buck变换器存在的低频波动.仿真与实验结果验证了理论分析的正确性.     

测量微观不平度的90°相移激光干涉仪

叙述了测量微观不平度的90°相移激光干涉仪的原理和构成。对这种新型干涉仪的性能及有关问题作了讨论。测量结果的计算和样品扫描的控制，由个人计算机完成。垂直分辨率达1um，横向分辨率达10μm。实验结果证明了系统的稳定性。     

快速稳压PSM电源主回路及补偿网络设计

针对NBI系统中单个脉冲调压电源模块(PSM)直流输出电压不可调、精度低、电压超调大,提出了在PSM电源模块输出侧串联一个调压电源的方法。为了使调压电源的系统有良好的动态性能,设计了一个TYPE-III补偿网络。最后搭建了一台样机,实验结果验证了主回路设计的正确性,为制造单个PSM电源测试台奠定了基础。     

盐水溶液跨混合纤维素膜扩散机制的定量可视化实验研究

介绍了一种改进的高时空分辨率相移干涉仪,测量了不同浓度的NaCl溶液跨过5 μm孔径醋酸-硝酸混合纤维素膜进入去离子水的跨膜扩散过程。实验观察到NaCl溶液在膜-液界面附近的质量输运行为受膜结构的影响而表现出的特征:相对分散的浓度高值分布、均流传质现象、对流的快速纵向进行和横向扩散的缓慢发展等。实验计算得10.0 mg/mL、7.5 mg/mL、5.0mg/mL、2.5 mg/mL 和 1.0 mg/mL 的 NaCl 溶液跨膜传质系数分别为 3.0×10~(-6) m~2/s、8.5×10-7 m~2/s、7.8×10~(-7)m~2/s、2.9× 10~(-7)m~2/s和6.0×10~(-8)m~2/s。本实验结果可为跨膜扩散机理的研究提供参考。     

相移数字全息子图拼接研究

 将全息图拼接技术应用到相移数字全息术中,改善再现像的质量。用全息图强度相关原理进行全息图拼接,再通过标准四步算法对拼接后的全息图进行运算,恢复原始物光。作为对比,对没有拼接的全息图进行了同样的操作。计算机模拟实验证明该全息图拼接技术可明显提高再现像的质量。同时,通过对光学实验获得的全息图进行零填充和拼接对比研究证明,前者只能提高系统成像的细节显示能力,后者能够提高再现像的分辨率和视场大小。     

用于0.35 μm接触孔图形相移掩模研究

基于霍普金斯（Ｈｏｐｋｉｎｓ）理论,通过计算０．３５μｍ方孔的传统透射掩模、边缘相移掩模部分边缘相移掩模、辅助相移掩模以及衰减相移掩模的硅片表面空间像的光强分布,找出了适合于各种相移掩模的最佳参数。其中衰减相移掩模对提高光刻分辨率和增加焦深最为明显,尤其在相干因子（σ）较小时更是如此。     

Optimum optics for die-to-wafer-like image mask inspection

The most annoying problem relating to the sensitivity of mask inspection systems is the encountering of false signals arising from nuisance defects. In order to overcome this problem, we have previously proposed a new algorithm for die-to-wafer-like image (D-to-WI) in real time. This paper describes the optimum mask inspection optics for the D-to-WI mask inspection. We examine the optimum mask inspection optics with numerical simulation for various numerical apertures (NAs) and partial coherence factors (σ) in these optics. The simulated result shows that the optimum mask inspection optics for the D-to-WI mask inspection has NA 0.9 and σ = 0.95 for an ArF-6%-phase shift mask (PSM) 260/260 nm line/space pattern on the mask plane, in which the 193 nm-ArF scanner has NA 0.93, σ = 0.92 − 0.92/0.3 annular illumination, reduction factor of ×4, and circular polarization incident light.     

Transmission tomography of proportional scattering media

Reconstruction of the extinction coefficient spatial distribution in transmission tomography of proportional scattering media (PSM) is considered. An exact analytical solution to the transport equation for PSM is derived for an arbitrary distribution of radiation sources. An inverse problem of tomography as applied to PSM is solved exactly without making additional assumptions. Difficulties associated with implementation of the tomographic algorithm and with uncertain knowledge of the proportionality coefficient in PSM are discussed. The results obtained may be useful in designing new types of transmission optical tomographs.     

Research on improving the transverse resolution of binary optical element by digital-division-mask technique

We present the digital-division-mask technique for the first time to solve the problem of decline in transverse resolution, which is caused by using digital micro-mirror device (DMD) to make binary optical elements (BOEs). One high-frequency gray-tone mask can be divided into several low-frequency masks by fixed or variable low-frequency period sampling. And the superimposed lithography effect of these low-frequency masks in the spatial or temporal domain is the same as that of the original high-frequency gray-tone mask. The paper firstly analyzes the digital-division-mask technique in theory and describes the feasibility and advantages. Then taking the diffractive surface fabrication of refractive-diffractive hybrid lens as an example, we conclude that the digital-division-mask technique improves the edge sharpness of lithography pattern, and enhances the diffractive efficiency of BOEs by experiment.     

Lie algebroid morphisms, Poisson sigma models, and off-shell closed gauge symmetries

Chern–Simons (CS) gauge theories in three dimensions and the Poisson sigma model (PSM) in two dimensions are examples of the same theory, if their field equations are interpreted as morphisms of Lie algebroids and their symmetries (on-shell) as homotopies of such morphisms. We point out that the (off-shell) gauge symmetries of the PSM in the literature are not globally well defined for non-parallelizable Poisson manifolds and propose a covariant definition of the off-shell gauge symmetries as left action of some finite-dimensional Lie algebroid.

Our approach allows us to avoid complications arising in the infinite-dimensional super-geometry of the BV- and AKSZ-formalism. This preprint is a starting point in a series of papers meant to introduce Yang–Mills type gauge theories of Lie algebroids, which include the standard YM theory, gerbes, and the PSM.     

超分辨近场结构光盘读出信号的计算模型

给出了超分辨近场结构光盘(Super RENS)读出信号的计算模型。以时域有限差分法为基础,结合高斯光束矢量模型和衍射方法,通过计算得到了物镜出瞳上的读出信号。计算结果表明,Super RENS具有超衍射极限的空间分辨能力,并且其读出信号的特征完全不同于传统光盘。     

Surface layer reflective index changes of Au nanoparticle functionalized porous silicon microcavity for DNA detection

A technique is demonstrated to detect DNA hybridization based on surface layer of Au/porous silicon microcavity (Au/PSM) substrate for very small amount of biomolecules. Simulations show that the increase of effective refractive index for the first layer of PSM will cause a blue shift for its reflectance spectrum, and the blue shift becomes less with the increase of refractive index for one more layers. In experiments, such a blue shift of reflectance spectrum of PSM comes from the increase of refractive index by DNA hybridization on the surface. The detection limit of Au/PSM biosensor is 15.15 nM for 19-base pair DNA, which is comparable to that of reported biosensors based on porous silicon (PS). Therefore such an Au/PSM could be very useful to develop simple, rapid and sensitive optical biosensors when the amount of target is very small.     

Stencil lithography of gold-black IR absorption coatings

Gold black coatings are deposited through a stencil shadow mask to produce infrared-absorbing patterns with sub-mm lateral dimensions. Such dimensions match the characteristic pitch of Long Wave Infrared (LWIR) array bolometers. Infrared spectral imaging with sub-micron spatial resolution reveals the spatial distribution of absorption across the pattern.