Effect of Molecular Weight of Surfactant in Nano Ceria Slurry on Shallow Trench Isolation Chemical Mechanical Polishing (CMP)

Abstract

We examined the effect of the molecular weight of surfactants in ceria slurry during chemical mechanical polishing (CMP) for shallow trench isolation (STI). We found that for a surfactant with a higher molecular weight, the oxide removal rate decreased drastically as the surfactant concentration increased, but in the case of a lower molecular weight, it only slightly decreased. In addition, slurries whose surfactants had lower molecular weights maintained a higher nitride removal rate with increasing surfactant concentration. The results showed that the molecular weight and surfactant concentration have complex effects on the oxide removal rate and the oxide-to-nitride removal selectivity.

Pad roughness variation and its effect on material removal profile in ceria-based CMP slurry

“…The viscosity adjustment of parameters was interpreted as being a more effective method for improvement of removal rate profile. We especially believe that higher viscosity slurry with organic surfactant as additive can prevent the ceria abrasives to roughen the pad surface even though the oxide removal rate goes down because of it (Lim et al, 2005;Kang et al, 2004;Doi, 2007).…”

Consumables for Advanced Shallow Trench Isolation (STI)

“…Kang et al [24] investigated the effect of anionic surfactants on the oxide:nitride selectivity. As shown in Fig.…”

“…24 Force measurements for silica particles and ceria thin film as a function of pH.EFFECT OF SLURRY pH…”

Novel Use of Surfactants in Copper Chemical Mechanical Polishing (CMP)

“…Spontaneous organized molecular assemblies on the surface of electronic materials, one of the concepts of self-assembled monolayers (SAMs), have widened the application of the adsorption of surfactants at the solid-liquid interface to other areas such as nano-patterning [10]. This concept of SAMs can also be applied to CMP, not for particulate stabilization but for the maximization of the topographical selectivity to increase planarization efficiency and optimize material removal selectivity [11,12]. Surfactant layers that are adsorbed on a metal or a dielectric surface can act as inhibiting layers against unfavorable chemicaletching during CMP.…”