关键词: 电镀铜, PEG, 分子量, 微孔填充, 阴极极化, 结晶度

Abstract: The effect of the polyethylene glycol(PEG) molecular weight(MW) upon via-hole filling with diameter of 50 μm and aspect ratio of 1 in the acid copper plating solution was studied.The cathodic polarization in copper electroplating bath with PEG of different molecule weights was investigated by linear sweep voltammetry.The surface roughness,crystallography,and the resistivity of copper films were characterized by X-ray diffraction(XRD),atomic force microscopy(AFM) and the four-point probe measurements.The results showed that the polarization on the cathode and the hole-filling capability of electroplating copper bath were increased evidently with an increase of PEG molecular weight from 600 to 8000.When the PEG MW was larger than 6000 in electroplating bath,a void-free filling was achieved.While the surface roughness,resistivity and crystallinity of plated Cu film were decreased with an increase of PEG molecular weight from 600 to 8000.

Key words: copper electrodeposition, PEG, molecular weight, hole-filling, cathodic polarization, crystallinity