利用白光扫描干涉测量表面微观形貌

由于激光显微干涉只能测量表面微观形貌的相对高度值,不能进行绝对测量,本文提出了白光显微干涉测量方法,研制了测量仪器,并对CCD像素格值和PZT进行了标定.该仪器以白光干涉理论为基础,利用空间频域算法计算白光干涉图零级条纹中心位置,根据零级条纹中心移动量来得到被测工件表面微观形貌.对被测工件表面进行了测试,试验结果表明:...     

一种可溯源原子力探针显微镜

研制了一种基于白光干涉的可溯源原子力探针扫描显微镜,提出了一种稳健的白光干涉零级条纹定位算法,建立了一套高分辨激光干涉位移测量系统。在此基础上提出了一种探针标定方法,实现微纳表面可溯源测量。通过对台阶高度为(21.4±1.5)nm的标准光栅进行10次重复测量,其结果的平均值为21.56 nm,标准差为0.51 nm;同时对高度为150 nm的三维特征样件进行了三维测量,验证了所研制仪器测量的准确性和稳定性。     

基于白光相移干涉术的微结构几何尺寸表征

将Carré等步长相移法与白光垂直扫描相结合形成了一种白光等步长相移算法,该方法快速、准确、非接触,垂直分辨力可达亚纳米级.测量系统集成了Mirau显微干涉物镜,并通过高精度压电陶瓷纳米定位器带动物镜进行垂直扫描.分析了Carré法应用于白光干涉信号的相位提取的精度,对不同扫描步距以及不同信噪比情况下的测量进行了计算机仿真,确定了测量参数.结合重心法将相位计算的数据范围直接定位于干涉信号的零级条纹,从而省去了相位解包裹过程.通过对微谐振器和标准台阶的测量说明了该方法的有效性,并使用白光相移干涉、白光垂直扫描和单色光相移干涉对44 nm标准台阶进行了测量,并对测量结果进行了比较.     

基于Linnik型白光显微干涉光谱测量方法

针对在复杂测量环境下实现薄膜类样品的高精度测量需求,基于白光干涉光谱测量理论,搭建了Linnik型白光显微干涉光谱测量系统,该系统具有较长的工作距离.系统采用5步相移算法实现相位信息的精确提取,通过对绝对距离以及标准薄膜样品的测试,验证了方法的可行性,并在此基础上利用系统实现了对微结构表面形貌和不同材料薄膜厚度的纳米级精度测量.     

基于扫描白光干涉法的接触式表面形貌轮廓测量仪

本文提出了一种以杠杆触针机构作为微位移传感器,将扫描白光干涉法运用于接触式表面形貌测量的轮廓仪.该仪器的理论分辩力可达纳米级,与垂直扫描测量工作台相结合,测量范围可达5mm.文中重点论述了该轮廓仪测量系统的构成,测量原理,干涉信号数据处理.     

基于空间频域算法的三维微观形貌的测量

白光干涉术测量表面形貌,解决了单色光干涉测量中的相位不确定困扰。基于扫描白光干涉术的空间频域算法,具有受噪声影响小、计算精度高的优点。运用这一算法通过Mirau扫描干涉显微镜对台阶状样品表面进行了两次白光扫描测试,得出了台阶表面形貌结果,且两次测量的台阶高度相差不超过1 nm。同时,利用Zygo Newview 7200白光形貌仪对同一样品表面进行了测试对比,结果表明:两者得到的样品表面形貌一致,台阶高度相差0.9 nm。此外,实验数据处理的结果还表明:运用空间频域算法进行分析时二阶以上的色散完全可以忽略。     

基于干涉显微原理的表面形貌测量系统

根据光学干涉显微法原理,设计开发了一套微纳结构表面形貌测量系统.该系统采用林尼克干涉显微镜,通过参考镜扫描的方法将扫描器与相移器集为一体,分别采用五步相移算法和基于采样定理的包络均方函数(SEST)算法实现相移干涉法(PSI)和垂直扫描干涉法(VSI)两种模式对微纳结构的表面形貌测量.为验证该系统性能,采用标准多刻线样板和标准台阶作为样件对VSI 和PSI 两种模式分别进行了测量实验.结果证明,该系统能够完成微纳结构表面形貌的快速精确测量,可以满足微电子、微机电系统中微纳结构的表面形貌测量要求.     

全视场外差白光干涉测量技术

为了解决传统白光干涉测量技术中对线性位移机构的位移精度要求过高的问题,本文提出了一种全视场外差白光干涉测量技术。该技术主要通过使用存在差频的白光干涉信号作为光源来实现在大扫描步长和低扫描精度条件下相干峰位置的高精度检测。本文首先建立了白光外差干涉的数学模型,再根据数学模型提供的光强信号特性提出了整体系统设计方案,然后对测量方案的可行性进行了实验验证。最后针对多种误差对算法计算精度的影响进行了理论分析和数据对比。误差分析的结果表明:白光外差干涉测量技术提供更高的测量精度和更好的抗干扰性能,有效地降低了传统白光干涉测量对线性位移机构精度的严苛依赖,为光学自由曲面检测技术提供了更多的可选解决方案。     

O.92PZN-0.08PT晶体的缺陷与畴结构研究

应用环境扫描电子显微术(ESEM)、原子力扫描显微术(AFM)、同步辐射白光形貌术(SRWBT)等形貌成像技术研究了0.92PZN-0.08PT晶体的表面缺陷形态与铁电畴结构.通过对畴结构动态演化的同步辐射形貌观察,可揭示出该晶体的结构相变过程.     

扫描探针显微镜在粗糙度、纳米尺寸、表面形貌观测方面的应用

扫描探针显微镜是近十几年来在表面特征、表面形貌观测方面最重大的进展之一，是纳米测量学的基本工具。叙述了扫描探针显微镜的工作原理、检测模式及在观察检测纳米级的粗糙度、微小尺寸、表面形貌方面的特点和方法，比较了原子力显微镜、常规的表面轮廓仪、干涉显微镜、扫描电子显微镜在表面特性、表面形貌观测方面的性能，着重介绍了扫描探针显微镜在粗糙度、纳米尺寸、表面形貌观测方面的应用和存在的问题。     

Combination of surface characterization techniques for investigating optical thin-film components

To meet the requirements of comprehensively characterizing the morphology of thin films and substrates, a suitable combination of different measuring techniques should be chosen, i.e., a nonoptical surface profile measurement should be used together with optical analysis. It is demonstrated on selected examples of fluoride and oxide films that the use of atomic force microscopy and light scattering fulfills the demand of appropriate quantitative characterization over a sufficiently large range of bandwidths.     

Electrodeposited biotinylated polypyrrole as an immobilization method for impedimetric immunosensors

The potentialities of an electrodeposited biotinylated polypyrrole film as an immobilization matrix for the fabrication of impedimetric immunosensors are described. Biotinylated antibody (anti-human IgG), used as a model system, was attached to free biotin groups on the electrogenerated polypyrrole film using avidin as a coupling reagent. The resulting recognition interface consisted of a highly oriented monolayer immobilized onto the polymer surface. Cyclic voltammetry was used to characterize the polymer film. Additionally, scanning electron microscopy and atomic force microscopy were used to investigate the morphology of the immobilized material. This immobilization method allows the obtention of a highly reproducible and stable device. The resulting immunosensor has a linear dynamic range of 10-80 ng.ml/sup -1/ of antigen and a detection limit of 10 pg.ml/sup -1/. Furthermore, this immunosensor exhibited minor loss in response after two regeneration steps.     

Catalyst-referred etching of silicon

A Si wafer and polysilicon deposited on a Si wafer were planarized using catalyst-referred etching (CARE). Two apparatuses were produced for local etching and for planarization. The local etching apparatus was used to planarize polysilicon and the planarization apparatus was used to planarize Si wafers. Platinum and hydrofluoric acid were used as the catalytic plate and the source of reactive species, respectively. The processed surfaces were observed by optical interferometry, atomic force microscopy (AFM) and scanning electron microscopy (SEM). The results indicate that the CARE-processed surface is flat and undamaged.     

Fabrication of nanoconcave surface for cell immobilization in cell-based chip

Nanostructured surface such as nanoconcave shape can be utilized as a bioplatform to immobilize cells. In this study, we present fabrication of Au-coated nanoconcave surface and some possibility of cell immobilization. Long-range ordered periodic patterns with concave shape were formed on aluminum substrate by electrochemical anodization process. The morphology and topography of nanoconcave surface was investigated by atomic force microscopy and scanning electron microscopy. The pore-pore distance and the pore depth of nanoconcave pattern were measured at 105 +/- 5 nm and 30 +/- 2 nm, respectively. After Au deposition, the pore depth within Au-coated concave surface was 15 +/- 2 nm. The topography of HeLa cells immobilized on the nanoconcave surface was observed by AFM combined with confocal microscopy. The result expected that the Au-coated nanoconcave surface may be used as new culture substrate for cells immobilization in cell-based chip.     

Polymeric nanospheres fabricated with natural emulsifiers for clinical administration of an anticancer drug paclitaxel (Taxol®)

Paclitaxel (Taxol®) is one of the most effective anticancer drugs found from nature in recent decades, which can treat various cancers including ovarian, breast, brain, colon and lung cancer, and AIDS-related cancer. Due to its low aqueous solubility, adjuvants such as Cremophor EL, which causes serious side effects, have to be used in its administration. Our aim is to develop an alternative delivery system to achieve better therapeutic effects with minimum side effects. Paclitaxel-loaded nanospheres of biodegradable polymers were prepared by an improved solvent extraction/evaporation technique. Phospholipids, cholesterol and vitamins were used to replace traditional chemical emulsifiers to achieve high encapsulation efficiency (EE) and desired release rate of the drug. Nanospheres prepared under various conditions are characterized by the light scattering for size and size distribution, the scanning electron microscopy (SEM) and the atomic force microscopy (AFM) for surface morphology; differential scanning calorimetry (DSC) for the physical status of the drug within the polymeric matrix; the zeta-potential measurement for the surface charge properties; and X-ray photoelectron spectroscopy (XPS) for the surface chemistry. In-vitro release kinetics were measured by high-performance liquid chromatography (HPLC). Best design was pursued to develop a product for cancer chemotherapy.     

White-light interferometer with dispersion: an accurate fiber-optic sensor for the measurement of distance

We present a fiber-optical sensor for distance measurement of smooth and rough surfaces that is based on white-light interferometry; the sensor measures the distance from the sample surface to the sensor head. Because white light is used, the measurement is absolute. The measurement uncertainty depends not on the aperture of the optical system but only on the properties of the rough surface and is commonly approximately 1 microm. The measurement range is approximately 1 mm. The sensor includes no mechanical moving parts; mechanical movement is replaced by the spectral decomposition of light at the interferometer output. The absence of mechanical moving parts enables a high measuring rate to be reached.     

高深宽比微结构深度测量技术的研究进展

高深宽比孔/槽微结构现广泛应用于微机电系统（MEMS）与三维集成电路（3D-IC）等领域,是微纳器件的基础性工艺结构。随着器件微型化与功能化的发展需求,孔/槽微结构的深宽比不断提升。深度作为重要参数对器件加工工艺、器件性能有直接影响,微孔/槽结构深度的精确测量具有重要意义,但测量方法面临巨大挑战,成为测量领域的难题之一。针对这一问题,按照非光学和光学测量方式将测量方法分为两大类,介绍了扫描电子显微镜、扫描探针术、白光显微干涉技术、共焦显微技术和反射光谱技术等测量方法的工作原理,在微孔/槽深度测量方面的研究现状,尝试从中总结每种测量方法的优缺点,最后,讨论了未来高深宽比微结构深度测量发展趋势以及研究重点,为之后高深宽比微结构深度的测量技术研究提供帮助。     

Complementary characterization techniques for identification of ferroelectric domains in KNbO3 single crystals

KNbO₃ single crystals are often utilized for their piezoelectric and optical properties. In this study the domain configurations in as-grown single crystals were investigated using reflected light microscopy, scanning electron microscopy and atomic force microscopy. Using atomic force microscopy it was possible to image the distortion induced on the crystal surface by the domain walls and to quantify the predicted angle between (001)_pc planes across these walls for the cases of both 90° domain walls and S walls. These features can also be imaged using the other two techniques. This direct measurement of surface distortion verifies the geometrical model of domain structures, and suggests that any possible strain energy considerations are minor in predicting the surface topography in the material after phase changes from the growth temperature.