The effect of different TSV electroplating levelers on the copper residual stress

Levelers have great influence on residual stress of electrodeposited film used in TSV. In this study, 2-MP (2-mercaptopyridine), JGB (Janus green B) and 2-ABT (2-aminobenzothiazole) are used as levelers to study the effects of different levelers on residual stress. The film stress deposited with different levelers decreases in the order of 2-MP, JGB and 2-ABT and closely related to grain size. Grain size is 15nm, 80nm, 150nm with 2-MP, JGB, 2-ABT respectively. So the larger the grain size, the smaller the tensile stress. Levelers inhibitory decreases in the order of 2-MP, JGB and 2-ABT and higher inhibitory of levelers induce finer grains. Preferred planes change from (200), (111) to (220) with increasing 2-MP and JGB in the solution. The texture coefficient of (220) plane keeps increasing with increasing of 2-ABT concentration. The film surface is rough with 2-MP and JGB as levelers while the surface is smooth with 2-ABT as levelers.