Heterojunction-Enhanced CeO₂-Based Core-Shell Abrasives for High-Efficiency Photoassisted Chemical Mechanical...

Area of Science:

• Materials Science
• Surface Chemistry
• Nanotechnology

Background:

• Traditional chemical mechanical polishing (CMP) faces efficiency limitations due to the restricted chemical activity of conventional abrasives.
• Developing abrasives with enhanced chemical activity is crucial for improving polishing performance.

Purpose of the Study:

• To develop a photoassisted in situ Ce³⁺ enrichment strategy for core-shell abrasives.
• To investigate the performance of Ce-doped SnO₂ (CTO) core and La-doped CeO₂ (LCO) shell (CTO@LCO) abrasives in CMP.
• To elucidate the mechanism behind photoassisted chemical mechanical polishing (PACMP).

Main Methods:

• Fabrication of CTO@LCO core-shell abrasives.
• Utilizing a type-II heterojunction for efficient photogenerated electron transfer.
• Experimental characterizations and first-principles calculations to analyze band structure and heterointerface.

Main Results:

• CTO@LCO abrasives achieved a material removal rate (MRR) of 608 nm/min for TFT-LCD glass and 315 nm/min for Si wafer.
• Achieved reduced surface roughness (Ra) of 0.277 nm for glass and 0.190 nm for Si wafer.
• Outperformed commercial CeO₂ abrasives by over 129% in MRR and 45% in Ra.

Conclusions:

• The photoassisted in situ Ce³⁺ enrichment strategy effectively enhances abrasive chemical activity.
• CTO@LCO core-shell abrasives demonstrate superior performance in PACMP for ultraprecision manufacturing.
• This work provides a new avenue for developing chemically activated abrasives for advanced CMP applications.