AVS 50th International Symposium
    Manufacturing Science and Technology Tuesday Sessions
       Session MS-TuP

Paper MS-TuP9
Corrosion Characteristics of Diffusion Barrier Ta in Copper CMP

Tuesday, November 4, 2003, 5:30 pm, Room Hall A-C

Session: Poster Session
Presenter: D.W. Lee, Chung-Ang University, Korea
Authors: D.W. Lee, Chung-Ang University, Korea
N.H. Kim, Chung-Ang University, Korea
J.H. Lim, Growell Telecom
S.Y. Kim, Dongbu-Anam Semiconductor
E.G. Chang, Chung-Ang University, Korea
Correspondent: Click to Email
The diffusion barriers are require for Cu metallization because of the higher diffusivity of Cu in Si and dielectrics. Several barrier materials such as TiN, W, and Ta(TaN) have been studied for diffusion barrier. Among them, Ta-based diffusion barrier has been put emphasis on presently. Ta-base diffusion barrier has no reaction with Cu, better adhesion to both Cu and dielectric, desirable microstucture against Cu diffusion, and heteroepitaxial relationship with Cu. On this study, The corrosion characteristics of the diffusion barrier Ta in Copper Chemical Mechanical Polishing has been investigated. Key experimental variables that has been investigated are the corrosion rate by different agents containing slurry of Cu CMP. Whenever Cu and Ta films were corroded adding each oxidizer, the corrosion rate of Ta was much lower than that of Cu. That is, the difference in the corrosion rates of Ta by oxidizer was not larger as compared with Cu. As corroded by complexing agents, the corrosion rate of Ta was close to 0. The corrosion rate of Ta increased as added HNO@footnote 1@ and CH@footnote 2@COOH compared with the reference slurry; on the other hand, it decreased with addition of HF. In addition, resulting corrosion rate went up with lower pH of agent. However, the corrosion rates by agents were significant small. Hence, it doesn't affect on the removal rate of Cu CMP practically. Consequently, this can be explained by assuming that the mechanical effect dominates than the chemical effect on the polishing rate of Ta(TaN). @FootnoteText@ @sub 3@ @sub 3@.