相對於直流電鍍，脈衝電鍍法可利用較大之電流密度而不至於使鍍層被燒壞或形成粉晶，並製備出具有高密度生長雙晶(growth twin)的純銅薄膜，可同時實現超高強度和高導電性，在微機電的相關應用上相當廣泛。
本研究主要以改變脈衝電鍍的頻率製備出具有高密度生長雙晶(growth twin)的銅鍍層，再利用XRD、EBSD (Electron Backscatter Diffraction Pattern)、four-point probe及nanoindenter分析，探討參數的改變，對於鍍層之優選方位、微觀組織(如晶粒尺寸、雙晶密度、優選方位)、電性、機械性質等的影響。
實驗結果發現，以不同脈衝電鍍頻率所製備之銅鍍層具有<100>、<111> fiber，除此之外，當脈衝電鍍頻率增加時 (11Hz-454Hz)，晶粒大小 (1.5 ~ 5.0 μm) 與雙晶密度 (44~ 72 %) 也隨之增加，使得銅鍍層的電阻率 (5.8 ~ 4.3 μΩ-cm) 略為減少，機械性質方面，由於高角度晶界以及雙晶晶界的影響，楊氏模數由146 GPa下降至76 GPa，鍍層硬度則約為2 GPa。

Comparing to DC plating, pulse plating using larger current density provides an alteration to fabricate a high density of growth twins at the same time having high strength and high electrical conductivity. It has popularly applications in MEMS (micro-electro mechanical devices) in the future.
In this study, we varied the pulse electrodeposited frequency to fabricate the copper films with high density of growth twin. XRD、EBSD (electron backscattering diffraction)、four point probe and nanoindentation, were used to analyze the properties of copper films, ie. preferred orientation, microstructure (grain size, twin density, preferred orientation), electric properties, and mechanical properties.
The results indicate that the deposited copper films reveal <100> and <111> fiber texture. Besides, as the pulse frequency increased from 11Hz to 454Hz, the grain size and twin fraction are in the range of 1.5 - 5.0 μm and 44- 72 %, respectively. The electric resistivity is between 5.8 and 4.3 μΩ-cm. For the mechanical properties, the Young’s modulus is in the range of 76-146 GPa, and the hardness are approximately 2 GPa by the effect of high angle grain boundaries and twin boundaries.

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