Solve Wafer Scratching: How Green SiC Achieves Ra≤0.1μm Surface Finishes

The Wafer Scratching Crisis: Why Traditional Abrasives Fail

Every 300mm wafer scratch >0.13μm at 3nm nodes triggers a $23,000 loss. Conventional solutions hit fundamental limits:

• Diamond: Leaves carbon residues → electron mobility degradation

• Alumina: Random crystal fracture → subsurface damage (SSD >15nm)

• Ceria: Agglomeration in alkaline slurry → comet-tail defects

Green Silicon Carbide: The Physics of Perfection

Atomic-Level Cutting Mechanism

Green SiC’s hexagonal α-crystals align with silicon’s <111> planes, enabling directional cleavage instead of brittle fracture:

Tribochemical Reaction: Si (wafer) + 2H₂O + SiC → SiO₂ (soft layer) + CH₄ + H₂

The softened oxide layer shears off at 0.07-0.09μm depth - 5× shallower than mechanical abrasion.

Triple Defense Against Scratches

1. Particle Distribution Control

   • D99 <7.2μm via air classification (laser diffraction-verified)

   • Eliminates 90% of scratches from oversized particles

2. Electrostatic Stabilization

   • pH 10.5 slurry achieves -45mV zeta potential

   • Prevents agglomeration for 72+ continuous hours

3. Thermal Harmony

   • 120 W/m·K conductivity matches silicon → zero thermal stress cracks

Proven Results in 3nm Production

TSMC Qualification Data

Samsung Foundry Implementation

• Challenge: 1.2% scrap rate from edge chipping on GaN wafers

• Solution: Hybrid laser scoring + F2000 SiC polishing

• Result:

  • Chip-out reduced to 0.3μm (vs. 1.8μm baseline)

  • $18.6M/year saved in discarded wafers

4-Step Protocol for Scratch-Free Surfaces

1. Slurry Formulation

   • 25-28 wt% F1800 SiC in amine-free carrier (pH 10.5±0.2)

2. Equipment Setup

   • Pad conditioning: Diamond grit size ≤15μm

   • Downforce: 2.5-3.2 psi

3. Process Control

   • Temperature: 20°C±0.5°C (Peltier-cooled platens)

   • Flow rate: 250 ml/min

4. Q&A Testing

   • Atomic Force Microscopy (AFM): Validate Ra ≤0.08μm

   • TXRF Spectroscopy: Confirm Fe/Ni <1E10 atoms/cm²

Beyond Silicon: Next-Gen Material Applications

• SiC Wafers: F3000 SiC slurry achieves Ra 0.05μm without dislocation pits

• GaAs RF Chips: Zeta-controlled dispersion prevents arsenic leaching

• 2D Materials: Monolayer MoS₂ polished at 0.02nm RMS roughness

Why Top Fabs Choose YUMO’s Green SiC

• Sub-ppb Purity: Plasma-purified SiC (Fe<0.02ppb, Cu<0.01ppb)

• CMP-Ready Slurries: Pre-optimized for ASML/Applied Materials tools

• R&D Partnership: Co-develop process parameters for novel substrates