Department of Nano Science and Engineering, Kyungnam University, Woryeong-dong, Masanhabpo-gu, Changwon 631-701, Korea.
Microsc Microanal. 2013 Aug;19 Suppl 5:1-3. doi: 10.1017/S1431927613012208.
Nonconductive specimens for scanning electron microscopy or X-ray microanalysis are coated with conductive carbon in order to reduce charging. But carbon film absorbs X-ray fluxes causing errors in measuring chemical composition. Especially when the carbon content is measured, carbon coating not only blocks X-rays but also becomes a source of carbon X-rays. It is thus necessary to determine how much errors are induced by carbon coating, and how thick coating is allowed for the accurate measurement. In this study, quantitative analysis of carbon on silicon carbide with carbon coating films was attempted by electron probe microanalyzer. It was found that measured carbon content increased in a nonlinear manner up to 40% with a film thickness, whereas silicon content decreased slightly. Carbon X-ray intensity was determined by computer simulation, which increased in a linear manner with the thickness. The discrepancy was due to a nucleation and growth of islands and thus a change of density with a thickening of coating film.
为了减少电荷积累，扫描电子显微镜或 X 射线微分析用的非导电标本都用导电碳进行了覆盖。但是，碳膜会吸收 X 射线通量，从而导致化学成分测量出现误差。特别是在测量碳含量时，碳覆盖不仅会阻挡 X 射线，还会成为碳 X 射线的来源。因此，有必要确定碳覆盖会引起多少误差，以及允许多厚的覆盖层进行准确测量。在这项研究中，尝试使用电子探针微分析仪对碳化硅上的碳覆盖膜进行定量分析。结果发现，随着膜厚的增加，测量的碳含量呈非线性增加，最高可达 40%，而硅含量略有下降。通过计算机模拟确定了碳 X 射线强度，它随厚度呈线性增加。这种差异是由于岛的成核和生长，以及随着覆盖膜变厚密度的变化所致。
