Defect mitigation and reduction

Lift-off through surface repulsion. and mechanical/physical motion. 

Built-in charge repulsion b/n particle and wafer surface in basic environment. 

Upon contact with clean chemical, forms a complexion layer that passivates and protects the Cu surface from HM, DE...etc. 

Chelating agents are often added to cleaning chemicals to assist the removal of FM and PR, especially metallic oxide. Those with high surface charge to molecular weight ratio such as citric acid and oxalic acid are commonly used for post-CMP cleaning. Usually, small particles require lower friction force to be mechanically removed. However, for nanoscale abrasives currently used in the industry, van der Waals attraction 

In recent years, however, the usage of TMAH in the semiconductor industry raised serious concerns over industrial hygiene and safety. Fatal damage to nerves and muscles upon dermal contact with TMAH has been reported [35,36]. Therefore its usage should be prohibited and more benign clean chemicals used in the industry. 

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