2003 年 6 巻 7 号 p. 596-601
Through chip electrodes with high aspect ratios used for three dimensional packaging can offer the shortest interconnection and reduce signal delay. Copper has good compatibility to conventional multi layer interconnection in LSI and BEOL (back end of line process) . In this work, filling vias with higher aspect ratio, 10μm in square and 70 μm in depth, used for through chip electrodes was investigated. Removing overhang at via top is important to achieve perfect via fill of 10 μm in square and 70 μm in depth. With testing a series of electrodeposition conditions, conformal electrodeposits were obtained. With those conformal electrodeposits, seams and voids always remain at the via center. Perfect via filling without seams or voids was achieved by increasing leveler of JGB concentration to 30 mg/L. The electrodeposition time was reduced to 3.5 hrs by using two steps pulse reverse current.