Improvement of Fe-Ni Filling Performance by Complex Agents for the On-Chip Inductor Application

With the trend of miniaturization of electronic products, the integration of passive devices has become a feasible way to save space. In the field of electronic packaging, the concept of on-chip power supply system has been proposed, which vertically stacks passive components such as inductors, capacitors, and resistors on the chip, enabling device functionality to be achieved in areas of chip size. In order to improve the performance of integrated micro inductors as much as possible, this study mainly uses electrodeposition method to prepare Fe-Ni alloy thin films as inductive magnetic materials in the amino sulfonate system. The citric acid and lactic acid were replaced by a new complexing agent (such as Ethylene Diamine Tetraacetic Acid, EDTA) in the new electroplating solution. The scanning electron microscopy (SEM) was used to observe the coating morphology and the confocal laser scanning microscope (CLSM) was used to observe the filling profiles. In order to meet the needs of on-chip inductor magnetic cores of different shapes, the flatness of the electroplating pattern was also measured. A good filling performance was achieved on the patterns of linear patterns and circular patterns without leakage plating and microvoids. Above all, the Fe-Ni filling performance was improved by adopting the complex agents. This study helps to deepen our understanding of Fe- Ni magnetic thin film materials for on-chip inductors.