CMP Pad Conditioning Using the High-Pressure Micro-Jet Method

Area of Science:

• Materials Science
• Manufacturing Engineering

Background:

• Chemical mechanical polishing (CMP) is crucial for semiconductor manufacturing.
• Polishing pad performance degradation necessitates effective conditioning methods.
• Reducing CMP costs while maintaining high performance is a key industry challenge.

Purpose of the Study:

• To evaluate and compare the efficacy of high-pressure micro-jet (HPMJ) conditioning against traditional diamond conditioning for various polishing pads.
• To assess the impact of conditioning methods on material removal rate stability and pad longevity.
• To optimize CMP processes for improved performance and cost-effectiveness.

Main Methods:

• Experimentation with three polishing pad types: polyurethane, damping cloth, and non-woven fabric.
• Comparative analysis of HPMJ conditioning versus diamond conditioning.
• Scanning Electron Microscopy (SEM) to examine pad surface morphology and pore structure.
• Measurement of material removal rate fluctuations under different conditioning methods.

Main Results:

• HPMJ conditioning resulted in material removal rate fluctuation ranges of 2.73-3.75 μm/h, 1.38-1.99 μm/h, and 2.36-4.32 μm/h for the tested pads.
• Diamond conditioning showed wider fluctuation ranges: 1.80-4.14 μm/h, 1.02-2.09 μm/h, and 1.78-5.88 μm/h.
• SEM analysis revealed cleaner pad surfaces with unblocked pores after HPMJ conditioning, unlike diamond conditioning which left abrasive particles and blocked pores.

Conclusions:

• HPMJ conditioning technology significantly outperforms traditional diamond conditioning for polishing pads.
• HPMJ conditioning leads to a longer service life and more stable material removal rates.
• This method enhances polishing pad performance and reduces overall chemical mechanical polishing costs.