The saw street (also called scribe lane or kerf region) is the narrow strip of space intentionally left between adjacent dies on a semiconductor wafer. This area is reserved specifically for the dicing blade or laser to cut through when separating individual chips after wafer-level processing is complete.

Key Characteristics

• Typical Width: Ranges from about 30 µm to 200 µm, depending on the dicing method — laser dicing allows narrower streets than traditional blade dicing.
• Contents: Saw streets often contain test structures, alignment marks, process control monitors (PCMs), and dummy fill patterns used during fabrication but not part of the final die.
• Impact on Yield: Narrower saw streets mean more usable die area per wafer, directly improving die per wafer (DPW) and overall economics. Advanced fabs continuously work to shrink kerf width.

Why It Matters

If saw streets are too narrow, the dicing blade can damage active circuitry on adjacent dies, causing yield loss. If too wide, valuable wafer real estate is wasted. Optimizing saw street width is a balance between mechanical reliability during dicing, the space needed for process monitors, and maximizing the number of good dies per wafer.