Nanotopography impact and non-prestonian Behavior of ceria slurry in shallow trench isolation chemical mechanical polishing (STI-CMP)

We investigated the nanotopography impact on the post-chemical mechanical polishing (post-CMP) oxide thickness deviation (OTD) and the non-Prestonian behavior of ceria slurry with a surfactant. Not only the surfactant but also the slurry abrasive size influenced the non-Prestonian behavior and the nanotopography impact. We created a one-dimensional numerical simulation of the nanotopography impact by taking account of the non-Prestonian behavior of the slurry, and good agreement with the experimental results was obtained. After examining the mechanism of oxide surface planarization during CMP, an index to relate the non-Prestonian behavior of the slurry to the nanotopography impact was developed.