Lapping powder for grinding silicon wafer
Silicon wafer processing : Slicing → Grinding → Double-sided Lapping → Etching → CMP (Chemical Mechanical Polishing)
1. Double-sided Lapping (Free-Abrasive Lapping)
Mainstream products: Fujimi FO series abrasive powders and domestic aluminum oxide-based composite abrasive powders (as cost-effective alternatives).
Characteristics: Well-controlled, rounded particle morphology; moderate material removal rate; minimal subsurface damage; controllable scratching. These are the industry-standard abrasive powders for the traditional double-sided lapping of 12-inch and 8-inch silicon wafers.
Domestic equivalents: Aluminum oxide-based composite abrasive powders.
Note: These are not fused white aluminum oxide (white corundum)! White fused alumina (WFA) features sharp, angular grains that tend to cause deep subsurface damage and scratches. Consequently, it is rarely used in primary silicon wafer production lines for double-sided free-abrasive lapping. Its application is limited to tasks such as conditioning tooling or lapping plates, rather than the actual lapping of silicon wafers.
2. Post-slicing coarse lapping (to remove wire-saw kerf marks and large amounts of excess material)
Green silicon carbide (GC) micropowder (grades W10, W7, W5) offers fast cutting rates and excellent self-sharpening properties. It is primarily used for the coarse lapping of small-diameter silicon wafers and substrates for discrete devices. However, it is now rarely used for coarse lapping on 12-inch wafer production lines, as it is prone to causing deep subsurface damage.
3. Chemical-Mechanical Polishing (CMP) (for a final mirror-like finish; distinct from the abrasives used in double-sided free-abrasive lapping)
CMP processes do not utilize Fujimi FO-series polishing powders or their domestic alumina-based alternatives.
Mainstream approach: Colloidal silica (nano-SiO₂) slurries (e.g., Fujimi COMPOL, Cabot, or Fujifilm products).
Specialized applications: For heavily doped silicon or unique silicon samples, nano-alumina-based CMP slurries may be used in limited quantities.
4. Other niche applications (laboratory use, sample preparation)
Polycrystalline diamond micropowder: Used in scientific research or for small-batch, specialized silicon samples. While it offers a high material removal rate, it is too costly for mass-producing silicon wafers.
Today, we will focus on a domestic alumina-based composite lapping powder—a cost-effective alternative that has been validated in production environments and serves as a direct, full-performance replacement for Japan’s Fujimi FO series.
Chemical composition analysis report for the domestic alumina-based composite lapping powder.
