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Indexed by:期刊论文

Date of Publication:2013-02-01

Journal:MATERIALS AND MANUFACTURING PROCESSES

Included Journals:SCIE、EI

Volume:28

Issue:2

Page Number:207-212

ISSN No.:1042-6914

Key Words:Abrasives; CMP; Copper; ECMP; Electrochemistry; Permittivity; SiO2; TiO2

Abstract:Electro-Chemical Mechanical Polishing (ECMP) is a promising low-pressure copper planarization method for the interconnection containing low-k material. ECMP utilizes anodic dissolution of copper to raise the material removal rate. However, the surface roughness is usually not acceptable in ECMP because the selective removal ability of electrochemical dissolution is poor. Different permittivity abrasives have different influence on surface quality in ECMP. High permittivity abrasives can enhance selective removal ability to get better polishing results through aggrandizing the potential drop in electrode/electrolyte interface. In this article, three abrasives with different permittivity are compared using polishing experiments. The results show that rutile TiO2, permittivity of which is larger than anatase TiO2 and SiO2, gets the best surface quality among the three abrasives. The composition of electrolyte with rutile TiO2 was also optimized to improve polishing performance. The chosen electrolyte contains 0.5mol/L glycine, 0.1mol/L TSA, 1wt% rutile TiO2. The material removal rate got by using this electrolyte is 0.06mg/min and the surface roughness is Ra8.9nm.