engineering lots

Engineering Lots are small quantities of wafers processed through the fab for development, process characterization, or design validation purposes — not intended for production, engineering lots are used to evaluate new processes, test design changes, debug yield issues, and qualify process modifications.

Engineering Lot Types

• Process Development: Test new recipes, materials, or equipment — evaluate process capability before production.
• Design Validation: First silicon — build a new design to verify functionality.
• DOE (Design of Experiments): Systematic variation of process parameters — split lots with different conditions.
• Yield Learning: Short loops focusing on specific process modules — accelerate learning without full-flow wafers.

Why It Matters

• Risk Reduction: Engineering lots validate changes before they affect production — catch problems early.
• Speed: Small lots (1-5 wafers) move through the fab faster than full production lots (25 wafers).
• Cost: Engineering lots consume fab capacity — balancing development needs with production throughput is critical.

Engineering Lots are the fab's experiments — small-quantity wafer runs for development, validation, and learning without risking production throughput.