PECVD-Ti/TiNx barrier with multilayered amorphous structure and high thermal stability for copper metallization

Wen Fa Wu, Keng Liang Ou, Chang Pin Chou, Jwo Lun Hsu

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Ultrathin (10 nm) Ti films with an amorphous structure were deposited by low temperature (4 and H2 as reactants. Ammonia plasma was further employed to post-treat the PECVD-Ti barrier layer to improve barrier properties. An amorphous TiNx layer forms on the surface of the PECVD-Ti layer after ammonia plasma post-treatment. The resulting films have a multilayered amorphous Ti/TiNx structure. Furthermore, the effective resistivity of resulting Ti/TiNx film reduces to 122 μΩ cm. Improved barrier capability against Cu diffusion is found for the Ti/TiNx barrier layer because the Cu/TiNx/Ti/n+-p junction diodes retain low leakage current densities even after annealing at 500°C for 1 h. Ti/TiNx barrier layers present lengthened grain structures to effectively impede Cu diffusion, thus acting as much more effective barriers than are conventional Ti and TiN films.

Original languageEnglish
JournalElectrochemical and Solid-State Letters
Issue number2
Publication statusPublished - Feb 2003
Externally publishedYes


ASJC Scopus subject areas

  • Electrochemistry
  • Materials Science(all)

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