Reduction effect of line edge roughness on time-dependent dielectric breakdown lifetime of Cu/low-k interconnects by using CF 3 I etching

Eiichi Soda, Noriaki Oda, Sanae Ito, Seiichi Kondo, Shuichi Saito, Seiji Samukawa

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

The authors investigated the etching of grooves in low- k in Cu technology. Correlation between the line edge roughness (LER) and the time-dependent dielectric breakdown (TDDB) reliability for 100 nm pitch Cu interconnects was investigated. They controlled LER by using various gases to etch multilayer photoresist. C F3 I gas was found to reduce LER better than conventional gases such as C F4 and CH F3 because C F3 I has higher etching selectivity of photoresist against spin-on glass film. The LER did not affect measures of electrical performance such as wiring resistance, capacitance, and leakage current, but did affect TDDB lifetime because, according to their simulation, the electric field was strongly enhanced at curvatures in the interconnects. The maximum electric field (Emax) was also determined to evaluate the effect of LER on TDDB lifetime. All their results show that C F3 I etching is promising for creating reliable Cu interconnects with smaller pitches.

Original languageEnglish
Pages (from-to)649-653
Number of pages5
JournalJournal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures
Volume27
Issue number2
DOIs
Publication statusPublished - 2009 Apr 20

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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