Influence of D.I. Water Pressure and Purified $N_2$ Gas on the Inter Level Dielectric-Chemical Mechanical Polishing Process

탈이온수의 압력과 정제된 $N_2$ 가스가 ILD-CMP 공정에 미치는 영향

It is very important to understand the correlation of between inter layer dielectric(ILD) CMP process and various facility factors supplied to equipment system. In this paper, the correlation between the various facility factors supplied to CMP equipment system and ILD CMP process were studied. To prevent the partial over-polishing(edge hot-spot) generated in the wafer edge area during polishing, we analyzed various facilities supplied at supply system. With facility shortage of D.I. water(DIW) pressure, we introduced an adding purified $N_2(PN_2)$ gas in polishing head cleaning station for increasing a cleaning effect. DIW pressure and PN2 gas factors were not related with removal rate, but edge hot-spot of patterned wafer had a serious relation. We estimated two factors (DIW pressure and PN2 gas) for the improvement of CMP process. Especially, we obtained a uniform planarity in patterned wafer and prohibited more than 90% wafer edge over-polishing. In this study, we acknowledged that facility factors supplied to equipment system played an important role in ILD-CMP process.