CMP 공정에서 압력과 정반속도가 사파이어 웨이퍼 재료제거율에 미치는 영향

Abstract

Kumoh National Institute of Technology(Received January 15, 2016; Revised March 18, 2016; Accepted Mach 20, 2016)Abstract − This study investigates the characteristics of the sapphire wafer chemical mechanical polishing(CMP) process. The material removal rate is one of the most important factors since it has a significant impacton the production efficiency of a sapphire wafer. Some of the factors affecting the material removal rate includethe pressure, platen speed and slurry. Among the factors affecting the CMP process, we analyzed the trends inthe material removal rate and surface roughness, which are mechanical factors corresponding to both the pressureand platen speed, were analyzed. We also analyzed the increase in the material removal rate, which is pro-portional to the pressure and platen speed, using the Preston equation. In the experiment, after polishing a 4-inchsapphire wafer with increasing pressure and platen speed, we confirmed the material removal rate via thicknessmeasurements. Further, surface roughness measurements of the sapphire wafer were performed using atomicforce microscopy (AFM) equipment. Using the measurement results, we analyzed the trends in the surface rough-ness with the increase in material removal rate. In addition, the experimental results, confirmed that the materialremoval rate increases in proportion to the pressure and platen speed. However, the results showed no associationbetween the material removal rate and surface roughness. The surface roughness after the CMP process showeda largely consistent trend. This study demonstrates the possibility to improve the production efficiency of sap-phire wafer while maintaining stable quality via mechanical factors associated with the CMP process.Keywords − polishing(연마), roughness(표면거칠기), material removal rate( 재료제거율), sapphire wafer(사파이어 웨이퍼)