Scanning electron thermal absorption microscopy for light elements detection and quantitative chemical analysis

Ching-Che Lin¹, Shih-Ming Wang^1,2, Bor-Yi Chen¹, Cheng-Hung Chi^1*, I-Ling Chang², Chih-Wei Chang^1,3

¹Center for Condensed Matter Sciences, National Taiwan University, Taipei, Taiwan
²Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan
³Center of Atomic Initiative for New Materials (AI-MAT), National Taiwan University, Taipei, Taiwan

* Presenter:Cheng-Hung Chi, email:chenghung.chi.ep01g@g2.nctu.edu.tw

Recent developments in nanoscale thermal metrology using electron microscopy have made impressive advancements in measuring either phononic or thermal transport properties of nanoscale samples. However, chemical analysis, which traditionally belongs to the domain of X-ray spectroscopy, has never been considered a possibility. Here we introduce a direct thermal absorption measurement platform in scanning electron microscope (SEM) and demonstrate that its signal can be utilized for chemical analysis at nanoscales. We prove that the measured absorbance of materials is complementary to signals of backscattering electrons but exhibiting a much higher collection efficiency and signal-to-noise ratio. Thus, it not only enables successful detections of light elements/compounds under low acceleration voltages of SEM but also allows quantitative compositional analyses in agreement with simulations. The direct thermal absorption measurement platform would become an ideal tool for SEM, especially for thin films, light elements/compounds, or biological samples at nanoscales.

Keywords: Thermal absorption of nanoscale materials, Nanoscience and technology, Techniques and instrumentation, Scanning electron microscopy, Materials science