Effects of CMP Pad Conditioner Properties and Performance on Polishing Pad, Process and Wafer Removal Rate

摘要

The focus of this work is CMP pad conditioners and the impact of diamond shape, size, density and protrusion on pad cut rate, pad surface roughness and wafer removal rate. Conditioner properties such as diamond shape, density and protrusion were found to directly impact the pad cut rate and wafer removal rate. Conditioners with high variation in diamond protrusion and uneven diamond shapes exhibited high drop in pad cut rate and wafer removal rate over the test period. Conditioners with high and very aggressive diamonds led to uneven pad conditioning creating step like features on the pad. Diamonds show wearing off sharp edges and chipping of edges due to mechanical forces exerted on them during conditioning. Also diamonds on some of the tested conditioners were found to be missing or sheared off during conditioning due to the mechanical stress and weak bonding process.