Enhanced Performance of STI CMP by Pre-Irradiation Optimization of a Ce1-xYxO2/D-PVA-Based Slurry.

With the continuous development of the semiconductor industry, shallow trench isolation (STI) technology is facing increasingly stringent performance requirements. Building on previous research on the dual-action mechanism of CeO2/PVA abrasive particles, this study further optimized the performance of the abrasives through Y3+ doping modification. Combined with the results of ultraviolet spectroscopy analysis, photocatalytic degradation tests, and X-ray photoelectron spectroscopy (XPS) characterization, it was found that Ce0.96Y0.04O2/D-PVA abrasive particles exhibit the best photocatalytic effect. Therefore, based on the Ce0.96Y0.04O2/D-PVA system, the influence of pre-irradiation of the polishing slurry on the performance of STI CMP was further investigated. The study revealed that the polishing slurry pre-irradiated for 10 min achieved a SiO2 removal rate of 2540.5 Å/min, which was 43.91% higher than that of the non-pre-irradiated group. The Si3N4 removal rate was 61.53% lower than that of the non-pre-irradiated group, and the selectivity ratio increased by 276.32% to 14.3. Meanwhile, the surface roughness of SiO2 and Si3N4 was reduced to 0.139 and 0.128 nm, respectively, indicating a significant improvement in surface quality.