yield recovery

**Yield Recovery** is the **process of restoring yield after a yield excursion or systematic yield drop** — involving rapid root cause analysis, corrective action, re-qualification, and ramp-back to target yield levels, minimizing the total yield loss impact on production. **Yield Recovery Process** - **Detection**: SPC alerts, lot disposition failures, or inline inspection alarms signal the yield drop. - **Containment**: Hold affected lots, quarantine suspect tools, implement 100% inspection — prevent further damage. - **Root Cause**: Failure analysis (FA), defect review (DR), and engineering investigation to identify the cause. - **Corrective Action**: Fix the root cause — recipe adjustment, tool maintenance, material change, design fix. - **Verification**: Process qualification wafers confirm the fix — yield returns to target. **Why It Matters** - **Speed**: Faster recovery = less product loss — every hour of low yield costs thousands of dollars in lost production. - **Cost**: A 5% yield drop for one week at 10K WSPM = hundreds of lost die — potentially millions in revenue impact. - **Prevention**: Post-recovery analysis leads to preventive measures — documentation prevents recurrence. **Yield Recovery** is **manufacturing triage** — rapidly diagnosing and fixing yield drops to minimize production losses and restore full manufacturing capability.