1 University of Tubingen, Institute of Physical and Theoretical Chemistry, Tubingen, Germany.
2 Reutlingen University, Process Analysis and Technology, Reutlingen, Germany.
Appl Spectrosc. 2019 Jan;73(1):59-66. doi: 10.1177/0003702818797959. Epub 2018 Oct 11.
An ultraviolet visible (UV-Vis) spectroscopy method was developed that can quantitatively characterize a technical copper surface to determine oxide layers and organic impurities. The oxide layers were produced by a heating step at 175 ℃ for four different times (range = 1-10 min). Partial least squares (PLS) regression was used to establish a relation between the UV-Vis spectra and film thickness measurements using Auger electron spectroscopy depth profiles. The validation accuracy of the regression is in the range of approximately 2.3 nm. The prediction model allowed obtaining an estimation of the oxide layer thickness with an absolute error of 2.9 nm. Alternatively, already known methods cannot be used because of the high roughness of the technical copper surfaces. An integrating sphere is used to measure the diffuse reflectance of these surfaces, providing an average over all angles of illumination and observation.
开发了一种紫外可见（UV-Vis）光谱法，可定量表征技术铜表面以确定氧化层和有机杂质。氧化层是通过在 175°C 下加热四个不同时间（范围为 1-10 分钟）产生的。偏最小二乘（PLS）回归用于建立 UV-Vis 光谱与使用俄歇电子能谱深度剖面进行膜厚测量之间的关系。回归的验证精度约为 2.3nm。预测模型允许以 2.9nm 的绝对误差估算氧化层厚度。或者，由于技术铜表面的高粗糙度，无法使用已有的方法。积分球用于测量这些表面的漫反射率，提供所有照明和观察角度的平均值。
