Effects of Additives on Copper Electrodeposition in Submicrometer Trenches

Madoka Hasegawa, Yoshinori Negishi, Takuya Nakanishi, Tetsuya Osaka
2005 Journal of the Electrochemical Society  
Effects of the conventional bath additives ͓chloride ions ͑Cl − ͒, poly͑ethylene glycol͒ ͑PEG͒, bis͑3-sulfopropyl͒disulfide ͑SPS͒, and Janus green B ͑JGB͔͒ used in the damascene process on the filling of submicrometer trenches with electrodeposited copper were investigated by electrochemical polarization measurement and cross-sectional microscopy. The combination of Cl − and PEG inhibited copper deposition in the areas of opening of the trenches, while SPS accelerated it at the bottom.
more » ... ion curves showed that the degree of acceleration of copper deposition by SPS increases with the concentration of SPS. This SPS concentration-dependent acceleration accounts for the observed bottom-up growth. The addition of JGB inhibited copper deposition at the later stages of the filling process, leading to the suppression of the overfill phenomenon, although the bottom-up growth was also inhibited at high JGB concentrations. Bath agitation significantly enhanced the inhibition effect of JGB on the overfill phenomenon, without disturbing the bottom-up growth.
doi:10.1149/1.1867672 fatcat:tzwjlamujnfi3iuxchze5gxlcy