Recommend recipe re-cal on LITHO-07 pending the OPC model verification.
Recommend hold on M3 layer pending overlay metrology cross-check.
change management · resist / OPC
After the change on date, we are re-qualifying scope per the FMEA.
在 {變更} 於 {日期} 之後,我們依 FMEA 重新認證 {範圍}。Photo 變更管理用語。
After the resist supplier swap on 03/12, we are re-qualifying all critical layers per the FMEA.
After the OPC model update on 04/01, we are re-qualifying the contact layer per the FMEA.
— 真實場景 · Real Scenarios · 共 3 條 —
Email — Scanner Downtime Notice
Photo 部門早班負責人 6:30 AM 發給 fab 全 OPS 的 broadcast,scanner 突然 down。
Subject: [HEADS UP] Scanner LITHO-07 down — chuck swap in progress
All,
LITHO-07 went down at 04:55 this morning. Initial diagnosis is chuck temperature drift exceeding the recovery window — requires a chuck swap.
ETA recovery: 18:00 today (about 13 hours total downtime).
Impact:
- 12 lots currently in WIP queue rerouted to LITHO-09 and -11.
- Critical layer M2 on Product X delayed by ~6 hours.
- No customer-facing impact expected.
Equipment team is on site. I'll send a recovery update at 12:00 and again when tool is back qualified.
Thanks,
Photo OPS
相關縮寫:scanner · WIP · qualification
Conf Call — CD Shift Root Cause
PIE 主持 yield review,Photo 部門被點名解釋 CD shift 根因。Photo 工程師發言 90 秒。
Thanks. Quick recap on the CD shift situation on Product X.
We started seeing CD drift on the M2 photo step about two weeks ago. SPC tagged it on day three; we held the next two lots and ran a focused investigation.
Three things we found:
First, the drift correlates strongly with scanner LITHO-07 chamber B — Pearson r is 0.88 across 22 data points. LITHO-09 and -11 are clean.
Second, the root cause is reticle stage temperature drift after the routine PM on 03/12. The thermal recovery curve didn't return to baseline within the qualification window.
Third, the containment action is recipe re-cal on LITHO-07 and a tighter thermal qualification spec going forward. Recipe was re-cal'd Tuesday; we're monitoring SPC for the next 48 hours.
Long-term, we're updating the FMEA to include this thermal failure mode and adding an in-line thermal monitor.
Open to questions.
4.0 Root Cause Analysis — Overlay Excursion at LITHO-07
4.1 Symptom
Lot Q3-241 showed overlay error of 3.8 nm (spec 3.0 nm) on the M3 photo step. SPC alarmed at 02:14; lot held within 30 minutes.
4.2 Investigation Path
- Chamber correlation: error correlates with LITHO-07 chuck A (Pearson r = 0.93, n = 18). Chuck B and other scanners clean.
- Pareto: 70% of overlay deviation explained by stage Z-axis temperature drift since the 03/12 PM.
- Reticle alignment metrology confirmed reticle is within spec; not a mask issue.
4.3 Root Cause Statement
The overlay excursion is attributed to incomplete thermal recovery of LITHO-07 chuck A after the 03/12 PM, based on the SPC trend, chamber correlation, and stage thermal logs.
4.4 Containment
- All affected lots (4 lots, 96 wafers) on M3 layer held at WAT.
- Scanner LITHO-07 chuck A re-qualified with extended thermal soak (4 hours vs 2 hours previous).
- 100% overlay metrology on the next 10 lots through this tool.