Effects of the Solid Concentration of Ceria Slurry on the Removal Rate and Selectivity of Si Wafer during Chemical Mechanical Polishing

Abstract:

Shallow trench isolation via chemical mechanical polishing (CMP-STI) tests of Si wafers using CeO₂ slurry were studied. The impact of CeO₂ slurry's solid concentration on the SiO₂ removal rate and the selectivity ratio The effects of the solid concentration of CeO₂ slurry on the removal rate of SiO₂ and selectivity (SiO₂/Si₃N₄) were investigated. The CeO₂ abrasive was well matched to the XRD standard pattern, confirming that it had a cubic phase and the absence of any impurities. The SEM image showed that CeO₂ primary particles had a spherical-like shape with a size within 30-60 nm. Additionally, the prepared CeO₂ slurry showed a relatively high dispersion level. The wettability degree of the CeO₂ slurry on top of the Si wafer surface was also sufficient. Furthermore, results from polishing tests indicated that both the SiO₂ removal rate and the selectivity increased linearly with a rise in CeO₂ solid concentration.

• Periodical: Materials Science Forum (Volume 1129)
• Pages: 53-58
• DOI: https://doi.org/10.4028/p-QyfWN3
• Online since: October 2024
• Authors: Achmad Chafidz*, Karan Kumar Gupta, Chun Wei Yu, Chung Hsin Lu
• Keywords: CeO₂ Abrasive, Chemical Mechanical Polishing, Dispersant, Removal Rate, Shallow Trench Isolation

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