The Effect of the physico-chemical properties of cellulosic polymers on the Si wafer polishing process

Abstract

Cellulosic polymers were used as organic additives to reduce the wafer surface roughness during the polishing process. The physico-chemical affinity of the polymer for the wafer and the formation of a hydro-plane on the Si wafer surface were investigated to identify the role of the polymeric additives in the wafer-polishing process. Two different polymers, hydroxyethyl cellulose (HEC) and carboxymethyl cellulose (CMC), were employed as a surface modifier for the wafer. The wettability of the Si surface varied markedly between the different suspensions prepared with HEC and CMC due to different adsorptive behaviors. As a result, the suspension prepared with HEC reduced the haze level and micro-roughness of the wafer, enhancing overall polishing performance.