Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

作者：Yingying Hu, Md Rasadujjaman, Yanrong Wang, Jing Zhang, Yan Jiang, Mikhaı̈l R. Baklanov · 发表于：Coatings · 年份：2021 · DOI：10.3390/coatings11080937 · 被引用次数：19 · 研究领域：Semiconductor materials and devices、Metal and Thin Film Mechanics、Copper Interconnects and Reliability

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.