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This study demonstrated how the electroplating process capability was increased by identifying and reducing sources of strip-to-strip and in-strip variations. In particular, two factors causing variability in the plating thickness were studied - the stabilization point and the shield height of the plating system. The point of stabilization of a plating system is where attainment of a uniform plating thickness starts. The study showed that the point of stabilization of the strip-to-strip plating system is independent of the ramp-up parameters. Through a review of the ramp-up parameters, the stabilization point of the system was identified, and the number of dummy strips placed before and after the good strips to ensure the stability of the plating system was defined. On the other hand, the shield of the plating system is used to promote uniform current density along the strip during plating. The proper shield height tolerance was established in this study, resulting in a more uniform metal distribution within the strips and reducing plating thickness variability. Implementation of the correct number of dummy units and proper shield height tolerance increased the plating Cpk by 30-100%.
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