도금전류밀도에 따른 Ni박막의 결정립 크기, 전기비저항, 솔더 wetting angle 및 금속간화합물의 성장속도를 분석하였다. 도금전류밀도를 $5;mA/cm^2$에서 $40;mA/cm^2$로 증가시킴에 따라 Ni 박막의 표면 nodule의 크기가 감소하고 결정립이 미세화 되었으며, 전기비저항이 $7.37muOmega-cm$에서 $9.13muOmega-cm$로 증가하였다. $5;mA/cm^2$ 및 $10;mA/cm^2$에서 도금한 Ni 박막이 $40;mA/cm^2$에서 형성한 Ni 박막에 비해 전기비저항이 낮고 dense하며 계면 금속간화합물의 성장속도가 느리기 때문에 무연솔더의 UBM 용도로 더 적합할 것이다.
Characteristics of electroplated Ni films such as grain size, resistivity, solder wetting angle, and growth rate of intermetallic compound were evaluated as a function of electroplating current density. With increasing the electroplating current density from $5;mA/cm^2 $ to $40;mA/cm^2 $, the nodule size on the Ni film surface decreased, grain refinement occurred, and resistivity increased from $7.37muOmega-cm$ to $9.13muOmega-cm$. Compared with Ni film processed at $40;mA/cm^2 $, Ni films electroplated at $5;mA/cm^2 $ and $10;mA/cm^2 $ exhibited low resistivity, dense microstructure, and slow growth rate of intermetallic compound. Ni films electroplated at $5;mA/cm^2 $ and $10;mA/cm^2 $ are more suitable for Ni UBM application than that fabricated at $40;mA/cm^2 $.
