pH and Down Load Effects on Silicon Dioxide Dielectric CMP

Understanding the pH and down pressure effects is critical in elucidating the chemical and mechanical mechanisms in chemical mechanical polishing (CMP). This paper describes the variation in polishing rate by nonagglomerated silicon dioxide particles. The repulsive interaction force, solubility of amorphous silica, and total contact area at the pad-particles-wafer interface are important factors in determining polishing performance. In situ friction force measurements are used to detect the variation of interfacial contact during polishing. Surface finishes and interaction force of silica/silica were investigated using atomic force microscopy.