Study on Through Silicon Via (TSV) filling failures on various electroplating conditions

Abstract

TSV Cu filling failures in different electroplating condition were studied. Constant current electroplating was used for 5um x 50um and 10um x 100um TSV Cu filling. We investigated output voltage of defect-free TSV and TSV with defect to understand the different Cu growth behavior. Agitation during electroplating affects the range of applicable electroplating current. Compared to electroplating with agitation, higher current can be applied for 10um x 100um TSV without agitation while lower current for 5um x 50um TSV has Cu filling failure. Voltage variation during electroplating reveals the competitive adsorption of additives. Initial voltage drop is strongly related to TSV Cu filling failure.