Modeling Copper CMP Material Removal Rates Using Copper Surface Nanohardness

摘要

Copper nanohardness and etch rate measurements in various CMP solutions, in addition to alumina agglomerate size distribution measurements, were used in a model to predict material removal rates (MRR). Model predictions were compared to experimental copper CMP data. In general, the model predictions improved using measured nanohardness compared to predictions using a constant nanohardness of metallic copper. The model reasonably predicts MRR, indicating this model is applicable to the copper CMP process. However, when the solution pH was low ( < 4) the model overpredicted MRR, possibly due to a thin, hard passivation layer. Also, the model was very sensitive to the surface hardness in solutions of glycine and H_2O_2.