在低压扫描电子显微镜中研究柱内探测器微图对比度
Asia Matatyaho Ya'akobi1, Irina Davidovich1, Yeshayahu Talmon1
1Department of Chemical Engineering and The Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa 3200003, Israel.
概括
低压扫描电子显微镜 (SEM) 在2kV以下的成像通过调整光束加速电压和工作距离来优化对比度和分辨率. 最佳条件取决于样品的特性,绝缘基板有时会产生优异的结果.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
- 表面科学是一门学科.
背景情况:
- 扫描电子显微镜 (SEM) 传统上使用高束加速电压 (BAVs) 超过5kV.
- 进步使低压SEM (LVSEM) 低于2kV,提供高分辨率和无需充电的非导电样本的成像.
- 关于LVSEM中的电子样本相互作用和参数优化存在有限的研究.
研究的目的:
- 研究BAV和工作距离 (WD) 对微镜对比度和分辨率在LVSEM的影响.
- 确定碳纳米管和化纳米管等先进材料的最佳成像参数.
- 评估基板导电性对LVSEM成像质量的影响.
主要方法:
- 使用高分辨率的镜头内探测器进行LVSEM成像.
- 作为模型样本,检查了碳纳米管 (导电) 和化纳米管 (非导电).
- 使用晶片 (导电) 和玻璃片 (非导电) 作为基板.
主要成果:
- 最佳的LVSEM成像通常发生在低BAV (0.81.2kV) 和短WD (<3毫米) 时.
- 图像条件必须根据样本的特定特性进行定制,以获得最佳结果.
- 基板导电性显著影响微镜质量,绝缘基板有时可以提供更好的结果.
结论:
- 优化SEM成像参数对于有效的低压显微镜至关重要.
- 根据样本特征选择合适的基质可以提高LVSEM的性能.
- LVSEM为各种材料的高分辨率成像提供了一个强大的替代方案.
相关概念视频
Scanning Electron Microscopy
5.3K
A scanning electron microscope (SEM) is used to study the surface features of a sample by using an electron beam that scans the sample surface in a two-dimensional manner. Typically, areas between ~1 centimeter to 5 micrometers in width can be imaged. SEM can be used to image bacteria, viruses, tissues as well as larger samples like insects. Conventional SEM gives a magnification ranging from 20X to 30,000X and spatial resolution of 50 to 100 nanometers.
Fundamental Principles
Accelerated...
Fundamental Principles
Accelerated...
5.3K
Overview of Microscopy Techniques
14.7K
The early pioneers of microscopy opened a window into the invisible world of microorganisms. In 1830, Joseph Jackson Lister created an essentially modern light microscope. The 20th century saw the development of microscopes that leveraged nonvisible light, such as fluorescence microscopy that uses an ultraviolet light source and electron microscopy that uses short-wavelength electron beams. These advances significantly improved magnification, image resolution, and contrast. By comparison, the...
14.7K
Overview of Electron Microscopy
12.9K
The wavelengths of visible light ultimately limit the maximum theoretical resolution of images created by light microscopes. Most light microscopes can only magnify 1000X, and a few can magnify up to 1500X. Electrons, like electromagnetic radiation, can behave like waves, but with wavelengths of 0.005 nm, they produce significantly greater resolution up to 0.05 nm as compared to 500 nm for visible light. An electron microscope (EM) can create a sharp image that is magnified up to 2,000,000X.
12.9K
Phase Contrast and Differential Interference Contrast Microscopy
11.9K
Phase-Contrast Microscopes
In-phase-contrast microscopes, interference between light directly passing through a cell and light refracted by cellular components is used to create high-contrast, high-resolution images without staining. It is the oldest and simplest type of microscope that creates an image by altering the wavelengths of light rays passing through the specimen. Altered wavelength paths are created using an annular stop in the condenser. The annular stop produces a hollow cone of...
In-phase-contrast microscopes, interference between light directly passing through a cell and light refracted by cellular components is used to create high-contrast, high-resolution images without staining. It is the oldest and simplest type of microscope that creates an image by altering the wavelengths of light rays passing through the specimen. Altered wavelength paths are created using an annular stop in the condenser. The annular stop produces a hollow cone of...
11.9K
Electron Microscope Tomography and Single-particle Reconstruction
2.8K
Transmission electron microscopy (TEM) can be used to determine the 3D structure of biological samples with the help of techniques such as electron microscope tomography and single-particle reconstruction. While single-particle reconstruction can examine macromolecules and macromolecular complexes in vitro conditions only, tomography permits the study of cell components or small cells in vivo.
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
2.8K
Preparation of Samples for Electron Microscopy
6.7K
To be visualized by an electron microscope, either transmission or scanning, biological samples need to be fixed (stabilized) so the electron beam does not destroy them and dried thoroughly (desiccated/dehydrated) so the vacuum does not affect them. Fixation needs to be done as quickly as possible because the sample properties will start changing as soon as it is removed from its natural environment. For example, in a tissue sample, the oxygen levels begin decreasing, causing an altered...
6.7K


