Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (9): 2919.doi: 10.7503/cjcu20210225

• Physical Chemistry • Previous Articles     Next Articles

Effects of Additive on the Electrodeposition and Coating Structure in a Novel System of Electronic Copper Electroplating

LI Weiqing, JIN Lei, YANG Jiaqiang, Wang Zhaoyun, YANG Fangzu(), ZHAN Dongping(), TIAN Zhongqun   

  1. College of Chemistry and Chemical Engineering,State Key Laboratory of Physical Chemistry of Solid Surfaces,Engineering Research Center of Electrochemical Technology,Ministry of Education,Xiamen University,Xiamen 361005,China
  • Received:2021-04-06 Online:2021-09-10 Published:2021-09-08
  • Contact: YANG Fangzu E-mail:fzyang@xmu.edu.cn;dpzhan@xmu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21972118)

Abstract:

Electronic copper electroplating has important applications in the advanced electronic manufactu-ring industry. In this work, the effects of the additive XNS(a mixture of polyamine and nitrogen-containing compounds) on the coating structure in the novel, weakly alkaline and citrate-based multi-coordination system for copper electronic electroplating with low concentration of main salts(10 g/L copper sulfate) was investiga-ted. The constant current deposition experiments indicate that the additive XNS can increase the current efficiency of copper electrodeposition, which achieves 95.4% at a current density of 2.0 A/dm2 and increases by 17.5% comparing to the electroplating system without XNS. Electrochemical experiments prove that the additive XNS can change the cathodic reduction of Cu(Ⅱ) cations, i.e., in presence of XNS which is a one-step two-electron process[Cu(Ⅱ)+2e→Cu], and in absence of XNS which is a two-step one-electron processes [Cu(Ⅱ)+e→Cu(Ⅰ)+e→Cu], and improves the reduction current density of Cu electrodeposition. Although additive XNS can accelerate copper electrodeposition rate, the coating surface of Cu becomes much finer and neater. At the current density of 2.0 A/dm2, the crystal structure of copper coating is reconstructed from Cu(111) facet to Cu(200) facet, presenting highly preferred crystal orientation in the presence of XNS.

Key words: Electronic copper electroplating, Additive, Multi coordination, Weakly alkaline and low concentration process, Highly preferred crystal orientation

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