Mizuki Nagai

Electroplating copper filling for 3D packaging

Electroplating technology for via filling with copper for three-dimensional packaging is one of the strong candidates. The Cu electroplating technology for perfect via filling is discussed in this paper. A plating solution was prepared, in which plating deposition potential was found to be influential on its solution flow rate. The characteristics of organic additives in the plating solution were electrochemically measured with a rotary electrode so as to evaluate the influence of the solution flow and agitation on the organic additive functions. Optimization of organic additive concentrations and ratios in the plating solution was tried in order to establish the bottom-up growth in electroplating for perfect via filling. The selected plating solutions were applied to a dip-type plating system and evaluated by using the paddle agitation of the plating system. The combination of the plating system and plating solution showed the perfect filling of the high-aspect ratio via on a 300mm wafer.