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

Paper MS-TuP6
Effects of Oxidant on Polishing Selectivity in the Chemical Mechanical Planarization of W/Ti/TiN Layer

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

Session: Poster Session
Presenter: K.J. Lee, DAEBUL University, Korea
Authors: K.J. Lee, DAEBUL University, Korea
Y.-J. Seo, DAEBUL University, Korea
S.Y. Kim, ANAM Semicondctor Co., Inc., Korea
W.S. Lee, Chosun University, Korea
Correspondent: Click to Email
Tungsten is widely used as a plug for the multi-level interconnection structures. However, due to the poor adhesive properties of tungsten on SiO2 layer, the Ti/TiN barrier layer is usually deposited onto SiO@sub 2@ for increasing adhesion ability with tungsten film. Generally, for the tungsten-chemical mechanical polishing (W-CMP) process, the passivation layer on the tungsten surface during CMP plays an important role. In this paper, the effects of oxidants controlling the polishing selectivity of W/Ti/TiN layer were investigated. The alumina(Al@sub 2@O@sub3@) abrasive containing slurry with 5 % H@SUB2@O@SUB2@ as the oxidizer was studied. As our preliminary experimental results, very low removal rates were observed for the case of no-oxidant slurry. This low removal rate is only due to the mechanical abrasive force. However, for Ti and TiN with 5 % H@SUB2@O@SUB2@ oxidizer, different removal rate was observed. The removal mechanism of Ti during CMP is mainly due to mechanical abrasive, whereas for TiN, it is due to the formation of metastable soluble peroxide complex. This work was supported by Korea Research Foundation Grant(KRF-2002-005-D00011).