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

Paper MS-TuP7
Slurry Characteristics by Surfactant Condition at Copper CMP Process

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

Session: Poster Session
Presenter: I.P. Kim, Chung-Ang University, Korea
Authors: I.P. Kim, Chung-Ang University, Korea
N.H. Kim, Chung-Ang University, Korea
J.H. Lim, Growell Telecom
S.Y. Kim, Dongbu-Anam Semiconductor, Korea
E.G. Chang, Chung-Ang University, Korea
Correspondent: Click to Email
Copper is rapidly replacing aluminum interconnections due to its higher conductivity and lower electrical resistance in the semiconductor industry. Therefore, CMP (chemical mechanical polishing) is essential technology in microelectronic fabrication for the planarization of globally complex device topography. In this study, we evaluated the characteristics by the addition of 3 different kinds of nonionic surfactant to improve the dispersion stability of slurries. Slurry stability is an issue in any industry in which settling of particles can result in poor performance. So we observed the variation of particle size and settling rate when the concentration and addition time of surfactant are changed. When the surfactant is added after milling process, the particle size and pH became low. It is supposed that the particle agglomeration was disturbed by adsorption of surfactant on alumina abrasive. The settling rate was relatively stable when nonionic surfactant is added about 0.1-1.0 wt%. When molecular weight (MW) is too small like Brij 35, it was appeared low effect on dispersion stability. It is assumed that it can't prevent coagulation and subsequent settling with too small MW. The proper quality of MW for slurry stability was presented about 500,000. Consequently, the addition of nonionic surfactant to alumina slurry has been shown to have very good effect on slurry stabilization. If we apply these results to copper CMP process, it is thought that we will be able to obtain better yield.