Effect of post-CMP cleaning on electrochemical characteristics of Cu and Ti in patterned wafer

Kyung Min Noh, Eun Kyung Kim, Yong Keun Lee, Yun Mo Sung

Research output: Contribution to journalArticle

Abstract

The effects of post-CMP cleaning on the chemical and galvanic corrosion of copper (Cu) and titanium (Ti) were studied in patterned silicon (Si) wafers. First, variation of the corrosion rate was investigated as a function of the concentration of citric acid that was included in both the CMP slurry and the post-CMP solution. The open circuit potential (OCP) of Cu decreased as the citric acid concentration increased. In contrast with Cu, the OCP of titanium (Ti) increased as this concentration increased. The gap in the OCP between Cu and Ti increased as citric acid concentration increased, which increased the galvanic corrosion rate between Cu and Ti. The corrosion rates of Cu showed a linear relationship with the concentrations of citric acid. Second, the effect of Triton X-100®, a nonionic surfactant, in a post-CMP solution on the electrochemical characteristics of the specimens was also investigated. The OCP of Cu decreased as the surfactant concentration increased. In contrast with Cu, the OCP of Ti increased greatly as this concentration increased. Given that Triton X-100® changes its micelle structure according to its concentration in the solution, the corrosion rate of each concentration was tested.

Original languageEnglish
Pages (from-to)174-178
Number of pages5
JournalKorean Journal of Materials Research
Volume19
Issue number3
DOIs
Publication statusPublished - 2009 Mar 1

Keywords

  • Organic acid surfactant chemical corrosion galvanic corrosion
  • Post-CMP cleaning

ASJC Scopus subject areas

  • Materials Science(all)

Fingerprint Dive into the research topics of 'Effect of post-CMP cleaning on electrochemical characteristics of Cu and Ti in patterned wafer'. Together they form a unique fingerprint.

  • Cite this