Attachment of silica and alumina nanoparticles as studied by QCM

Abstract

Silica and alumina abrasives are commonly used in Chemical Mechanical Planarization (CMP) processes. Unfortunately, post-CMP attachment of abrasive particles to polished surfaces is a significant problem, which adversely affects the device yield. These particles have to be efficiently removed in post-CMP cleaning process. In the present research, the authors applied quartz crystal microbalance to investigate the silica and alumina abrasive attachment to copper and silica surfaces in the presence of surface active CMP slurry components. For copper surfaces with adsorbed Benzotriazole (BTA), alumina and silica abrasives attached as separate particles regardless of the zeta potential sign. At SiO2 surfaces, in the presence of adsorbed CTAB structure silica particles preferentially attached. © 2013 Taylor & Francis Group.