Green silicon carbide (SiC) micro powder plays a critical role in the semiconductor industry, particularly in wafer processing, power electronics, and advanced packaging, due to its exceptional hardness, thermal conductivity, and chemical stability. Below are its key applications and technological advantages:
1. Primary Applications in Semiconductor Manufacturing
(1) Wafer Lapping & Polishing
Silicon (Si) & Silicon Carbide (SiC) Wafers:
Used in rough lapping (W20-W10) to remove saw marks and achieve flatness.
Final polishing (W1.5-W0.5) for ultra-smooth surfaces (Ra < 0.5 nm) in SiC epitaxial wafer production.
Compound Semiconductors (GaAs, GaN):
Essential for polishing GaN-on-SiC substrates for high-frequency/RF devices.
(2) Dicing & Cutting
Wafer Dicing Blades:
Mixed with resin bonds to create dicing saws for SiC and GaN wafers (reducing chipping).
Laser Dicing Assist:
Acts as an abrasive in laser-induced thermal cracking for clean edge cuts.
(3) Thermal Management
Thermal Interface Materials (TIMs):
Added to thermal greases/pads to enhance heat dissipation in high-power devices (e.g., IGBTs, SiC MOSFETs).
Heat Sink Coatings:
Plasma-sprayed SiC coatings improve heat spreader performance.
(4) CMP (Chemical Mechanical Planarization)
Slurry Additive:
Combines with oxidizers (e.g., H₂O₂) to polish SiC and sapphire substrates in LED/HEMT fabrication.
2. Why Green SiC? Key Advantages
| Property | Benefit in Semiconductor Applications |
|---|---|
| High Hardness (9.2 Mohs) | Effective for machining ultra-hard SiC/GaN wafers. |
| High Thermal Conductivity (120 W/m·K) | Improves heat dissipation in power electronics. |
| Chemical Inertness | Resists reaction with acids/alkalis during wet etching. |
| Controlled Purity (≥99.9%) | Prevents metal contamination (Fe, Al < 50 ppm). |
| Controllable Particle Size (0.1–50 μm) | Adaptable to lapping (coarse) and CMP (fine). |
3. Critical Process Parameters
Polishing:
For SiC wafers: Colloidal silica + SiC slurry, pH 10–11, 30–60 rpm.
Dicing:
Blade composition: 30–50% SiC, resin bond, spindle speed 30,000 rpm.
Thermal Pastes:
Optimal loading: 15–25% SiC micro powder (3–5 μm) in silicone matrix.
4. Emerging Applications
SiC Power Devices:
Used in substrate thinning for vertical SiC MOSFETs (improving yield).
Advanced Packaging:
Enhances fan-out wafer-level packaging (FOWLP) reliability by reducing warpage.
Quantum Computing:
Polishes superconducting qubit substrates (e.g., Nb on SiC).