Tantalum-ruthenium dioxide as a diffusion barrier between Pt bottom electrode and TiSi2 ohmic contact layer for high density capacitors

Dong Soo Yoon, Hong Koo Baik, Sung Man Lee, Sang In Lee

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

The effects of RuO2 addition on the barrier properties of the Ta layer were investigated at the temperature range of 650-800°C in air. For the Pt/Ta/TiSi2/poly-Si/SiO2/Si structure, its layer structure was completely collapsed after annealing at 650°C, resulting in higher total resistance and Schottky characteristics. For the Pt/Ta+RuO2/TiSi2/poly-Si/SiO2/Si structure, however, it exhibited the lower total resistance and ohmic characteristics, and its layer structure was retained up to 800°C. A Ta amorphous structure by the chemically strong Ta-O or Ta-Ru-O bonds and nonstoichiometric, nanocrystalline RuOx resulted in the formation of a conductive RuO2 phase in the Ta+RuO2 barrier film after an annealing, leading to the prevention of the interdiffusion of Pt, Si, and external oxygen through the diffusion barrier as well as surface oxidation up to 800°C. Therefore, the thermal stability for the Pt/Ta+RuO2/TiSi2/poly-Si/SiO2/Si structure was higher than that for Pt/Ta/TiSi2/poly-Si/SiO2/Si structure.

Original languageEnglish
Pages (from-to)2544-2549
Number of pages6
JournalJournal of Applied Physics
Volume86
Issue number5
DOIs
Publication statusPublished - 1999 Sep

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

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