Effect of Various Surfactants On Surface Roughness Reduction During Cobalt “Buff Step” CMP

In this paper, effect of various surfactants on surface roughness reduction during cobalt “Buff step” chemical mechanical planarization were investigated. Various surfactants were characterized by atomic force microscope (AFM), surface tension, contact angle, viscosity, zeta potential and material removal rate. The result showed that all kinds of surfactants inhibit the removal rate of Cobalt, Solution Containing anionic surfactant conduce to obtain small surface roughness compared with others. The mechanism of reducing cobalt surface roughness by surfactant is proposed.