Green Silicon Carbide (GC) Micropowder for Semiconductor Silicon Wafer Polishing
1. Product Overview
Green silicon carbide (GC) high-purity micropowder is a core free abrasive for silicon wafer slicing, lapping and pre-polishing in semiconductor manufacturing. It is formulated into water/glycol-based polishing slurry to remove saw marks, flatten wafer surfaces and reduce subsurface lattice damage before CMP fine polishing.
2. Core Properties for Wafer Processing
- Ultra-high purity, ultra-low metallic impuritiesSiC ≥99.0%, Fe₂O₃ ≤0.05%, magnetic substances <15ppm, minimal free carbon and heavy metals. No metal contamination on silicon wafers, avoids leakage current and carrier lifetime degradation of chips.
- Appropriate hardness & self-sharpening crystal morphologyMohs hardness 9.2–9.5, sharp equiaxed polyhedral grains. Balances high material removal rate and shallow subsurface damage compared with black SiC and alumina abrasives.
- Excellent chemical inertness & thermal stabilityInsoluble and non-reactive with acid/alkali polishing liquid; high thermal conductivity dissipates friction heat rapidly to prevent wafer thermal stress, warpage and micro-cracks during high-speed lapping.
- Controlled narrow particle size distributionStrict classification eliminates oversized coarse grains, prevents random surface scratches, stabilizes wafer TTV (total thickness variation) and roughness uniformity.
3.Typical Chemical Index for Semiconductor-Grade GC Powder
| Index | Standard Requirement |
|---|---|
| SiC Content | ≥99.0% |
| Fe₂O₃ | ≤0.05% |
| Free Carbon (F.C) | ≤0.10% |
| Magnetic Matter | ≤0.015% |
| SiO₂ Impurity | ≤0.20% |
| Heavy Metals (Pb, Cd, Cr, Ni) | Total <20ppm |
4，Standard Grit Selection for Silicon Wafer Polishing
| Grit Size | Typical D50 Particle Size | Application Scenario |
|---|---|---|
| GC 600# | ~22 μm | Coarse lapping, heavy removal of saw damage |
| GC 800# | ~16 μm | Intermediate rough lapping |
| GC 1200# | ~12 μm | Silicon ingot wire slicing, medium lapping |
| GC 1500# | ~8 μm | Fine lapping for thin semiconductor wafers |
| GC 2000#–6000# | 1–5 μm | Ultra-fine pre-polishing, edge chamfer, rework |
5，Working Principle of GC Polishing Slurry
Mix high-purity GC micro powder with deionized water or PEG carrier liquid to form suspended polishing slurry. Under pressure between lapping plate and silicon wafer, GC particles roll and micro-cut the silicon surface to evenly strip uneven peaks, realizing flattening without deep crystal lattice destruction. After lapping, wafers go through multi-stage cleaning to remove residual SiC particles before chemical mechanical polishing (CMP).