Advanced CMP processes for 450mm applications

A 450mm CMP tool is installed, calibrated, and process qualified on oxide CMP process before the STI, W, and Cu processes can be evaluated. With the new multi-area polishing heads, the oxide removal rates ∼ 1800 A/min and the WIWNU% (3a) ≤ 8% within the same polish table can be achieved with a fumed-silica based slurry on a traditional IC pad as the first trial. A small baseline of wafer run is performed on each process table and the WTW (wafer-to-wafer) and HTH (head-to-head) removal rate variations are then calculated. In each polish table, sufficient WTW removal rate variation were obtained and current best WTWNU(3σ) was 1.1%. The tuning of removal rates on each Head/Polish table can be achieved with the manufacturer's advanced technologies, based on the signals and parameters pulled from the tool during processing. These signals and parameters allow process engineers to check if the wafers are processed at the similar conditions on the polishing pads. Polish behaviors of different silica based slurries, fumed & colloidal silica, on the same polishing pad are compared. More process results on STI application will be shown in the final paper, mainly on 450mm blanket monitor wafers.