Effects of nano-scale particles in chemical mechanical polishing process

Abstract

Chemical mechanical polishing(CMP) is a manufacturing process used to achieve th e high levels of global and local planarity required. Currently, the slurries us ed in CMP usually contain particles at nano scale to accelerate the material rem ove ratio (MRR) and to optimize the planarity. Micro polar theory will provide a feasible candidate to describe the rheology of these fluids. It will provide so me insights into the mechanism to solve the flow equation of CMP with the micro- polar effect considered. The effects of micro polarity on load and moments are s imulated and computation results are given. The results show that micro-polarity will give rise to an increase in load capacity to a certain extent by increasin g the equivalent viscosity of the slurries, through which the material removal c an be accelerated. The size-dependent feature can be seen since it becomes more prominent with low pitch height and low pad velocity. The effects of micro-polar ity on material removal rate in CMP process were experimentally investigated by altering the polarity of the slurries, which support the theoretical analysis.