Mechanism and Applications of Chemical and Mechanical Polishing

The mechanism of chemical mechanical polishing (CMP) is so complicated because there is synergy between chemical and mechanical action. We studied the effect of particels in CMP by MD simulation theoreticaly and liquid jet simulation experimentaly. The results show that MD simulation and slurry jet test have the similar result. For MD simulation, during the collision there are material adhesion and transfer between particle and surface. The pit bottom is not flat in both MD simulation and collision test, this is because the particle rotates during the collision. The pit area and depth increase with the particle energy. The effect of chemical reaction under mechanical action in CMP is studied. With mechanical action, the density of exposed fresh surface increases during the CMP process. The thoretical analysis shows that the corrosion current with the mechanical action is extremely increased at least 100 times than the static corrosion. CMP applications in SKLT are also introduced in this presentation. We have developed CMP slurries for hard disk substrate, silicon wafer and sapphire wafer as LED substrate. These slurries have already been used in China.