Influences of edges and steep slopes in 3D interference and confocal microscopy
Influences of edges and steep slopes in 3D interference and confocal microscopy
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3D 干涉和共焦显微镜中边缘和陡坡的影响
DOI：
10.1117/12.2228307
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
P. Lehmann
中科院分区：
文献类型：
--
作者：
W. Xie;S. Hagemeier;C. Woidt;H. Hillmer;P. Lehmann
光学测量技术被广泛应用于高分辨率轮廓、地形和粗糙度测量中。在这方面，垂直扫描白光干涉仪和共焦显微镜在过去几十年中已成为成熟的仪器。测量结果的准确性不仅与测量仪器的类型和物理性质密切相关，而且与测量对象本身也密切相关。这项贡献侧重于使用不同数值孔径的白光干涉仪在边缘和高度台阶上发生的测量效果。如果边缘完全垂直，则蝙蝠翼效果会出现在高度台阶上。如果高度与波长之比(HWR)约为1/4或3/4，这些蝙蝠翼将显示最大高度，如果HWR值约为1/2的整数倍，则它们将消失。在此上下文中相关的波长是有效波长，即照明光的中心波长乘以称为数值孔径校正的校正系数。然而，在实践中，边缘通常不是完全垂直的。在这种情况下，测量结果也取决于表面高度函数的导数，并且根据HWR值，它们可能与理论和预测不同。对这些步骤的测量显示了取决于仪器横向分辨率的系统效应。在此背景下，使用放大倍数为100x、NA=0.9的Linnik干涉仪来表征由纳米压印技术产生的或多或少的矩形校准样品和准垂直结构的三维形貌。Linnik干涉仪配备了不同波长发射的LED光源，可以改变HWR值。这是可能的，因为高NA物镜显示相当有限的焦深，使得在该特定仪器中可以用焦点选通来代替时间相干选通。此外，还将测量结果与NA=0.55的米劳干涉仪的测量结果进行了比较。用NA为0.95的商用共聚焦显微镜作为进一步比较的参考仪器。为了解释不同白光干涉仪和彩色光干涉仪的实验结果，进行了考虑衍射效应的数值模拟。
Optical measurement techniques are widely applied in high-resolution contour, topography and roughness measurement. In this context vertical scanning white-light interferometers and confocal microscopes have become mature instruments over the last decades. The accuracy of measurement results is highly related not only to the type and physical properties of the measuring instruments, but also to the measurement object itself. This contribution focuses on measurement effects occurring at edges and height steps using white-light interferometers of different numerical apertures. If the edge is perfectly perpendicular, batwing effects appear at height steps. These batwings show maximum height if the height-to-wavelength-ratio (HWR) is about one forth or three forth, and they disappear if the HWR value is about an integer multiple of one half. The wavelength that is relevant in this context is the effective wavelength, ie the center wavelength of the illuminating light multiplied by a correction factor known as the numerical aperture correction. However, in practice the edges are usually not perfectly perpendicular. In this case, the measurement results depend also on the derivative of the surface height function and they may differ from theory and the prediction according to the HWR value. Measurements of such steps show systematical effects depending on the lateral resolution of the instrument. In this context, a Linnik interferometer with a magnification of 100x and NA= 0.9 is used to characterize the three dimensional topography of more or less rectangular calibration specimens and quasi-perpendicular structures produced by the nanoimprint technology. The Linnik interferometer is equipped with LED light sources emitting at different wavelengths, so that the HWR value can be changed. This is possible since the high NA objective lenses show a rather limited depth of focus such that the temporal coherence gating may be replaced by focal gating in this particular instrument. In addition, measurement results are compared with those achieved by a Mirau interferometer of NA= 0.55. A commercial confocal microscope with NA of 0.95 serves as a reference instrument for further comparison. Numerical simulations considering diffraction effects are carried out in order to explain the experimental results obtained by the different white and colored light interferometers.
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由于透射干涉显微镜的孔径而进行的校正
DOI：
--
发表时间：
1958
期刊：
影响因子：
--
作者：
E. Ingelstam;L. Johansson
通讯作者：
L. Johansson
第 4 章 – 相位成像
DOI：
--
发表时间：
1996
期刊：
影响因子：
--
作者：
T. Corle;G. Kino
通讯作者：
G. Kino
垂直扫描白光干涉仪的横向分辨率和传输特性。
影响因子：
1.9
作者：
Weichang Xie;P. Lehmann;J. Niehues
通讯作者：
J. Niehues
以矩形光栅为例的低相干干涉显微镜中的信号建模
影响因子：
3.8
作者：
W. Xie;P. Lehmann;J. Niehues;S. Tereschenko
通讯作者：
S. Tereschenko