在液相SEM中通过蒙特卡洛模拟测定样本可见性的高通量测定
Dian Yu1, Mia L San Gabriel1, Stas Dogel2
1Department of Materials Science and Engineering, University of Toronto, 184 College Street, Toronto, ON M5S 3E4, Canada.
概括
这项研究通过模拟样本可见性来优化液相扫描电子显微镜 (LP-SEM). 更薄的膜和二次电子增强了对比度和分辨率,即使在较低的电子能量.
科学领域:
- 材料科学 材料科学 材料科学
- 电子显微镜电子显微镜
- 计算建模 计算建模
背景情况:
- 液相扫描电子显微镜 (LP-SEM) 对于观察含水或液体样本至关重要.
- 在LP-SEM中优化图像质量和分辨率对于详细的纳米分析至关重要.
- 电子透明化 (Si3N4) 膜通常用于LP-SEM中的样品支器.
研究的目的:
- 调查各种参数对LP-SEM样本可见性的影响.
- 为了优化成像条件,提高对比度和空间分辨率.
- 在LP-SEM中减少蒙特卡洛模拟的计算时间.
主要方法:
- 开发了一个蒙特卡洛模拟工作流程.
- 使用了薄形样本几何和非均的扫描点间距.
- 分析了可见对比度和空间分辨率的值电流.
主要成果:
- 优化模拟工作流可以将计算时间减少两倍.
- 二次电子 (SEs) 可以在低至3keV的发生电子能量下,比回散电子 (BSEs) 更有效地可视化薄样本.
- 厚度为20nm或更小的Si3N4膜与高效的镜头内探测器相结合,可以改善SE成像.
- 空间分辨率随着膜和样品厚度的增加而下降.
结论:
- 薄的Si3N4膜 (≤20nm) 和二次电子成像对于高分辨率LP-SEM.是有效的.
- 蒙特卡洛模拟为优化LP-SEM参数提供了一个强大的工具.
- 该研究为改善LP-SEM中的样本可见性和空间分辨率提供了指导方针.
更多相关视频
09:58A Modular Microfluidic Technology for Systematic Studies of Colloidal Semiconductor Nanocrystals
Published on: May 10, 2018
9.7K
10:52Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
Published on: April 12, 2019
12.9K
相关概念视频
Overview of Electron Microscopy
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.
Scanning Electron Microscopy
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...
Transmission Electron Microscopy
In 1931, physicist Ernst Ruska—building on the idea that magnetic fields can direct an electron beam just as lenses can direct a beam of light in an optical microscope—developed the first prototype of the electron microscope. This development led to the development of the field of electron microscopy. In the transmission electron microscope (TEM), electrons are produced by a hot tungsten element and accelerated by a potential difference in an electron gun, which gives them up to 400 keV in...
Preparation of Samples for Electron Microscopy
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...
