Proposed Model for Copper CMP

We utilize the Kaufman model as a basis for understanding the removal mechanism in the CMP of copper. Specifically, we hypothesis that a CU2O film forms on the copper and that just as with tungsten, the surface film prevents the removal of the low-lying copper. However, we believe that the dominant mechanism for removal in the case of copper CMP is abrasion of material from the surface by the mechanical action, rather than direct dissolution of material at the metal surface. 

We hypothesize that the removal of copper during CMP is controlled by a two step process  

Removal of the abraded material from the vicinity of the copper surface. 

The term abraded material refers to copper and/or copper oxides (or other compounds that form the surface film) that are mechanically dislodged by the abrasive action. Removal of the material from the vicinity of the copper surface may be achieved by one or more of the following mechanisms  

Adsorption of the abraded material onto the abrasive article, or 

---