from datetime import datetime, timedelta
from typing import Dict, List
DEFECT_DETAILS: Dict[str, Dict] = {
"PARTICLE": {
"description": "Particles causing shorts/opens",
"likely_causes": [
"Chamber wall flaking after long PM interval",
"Worn ESC O-ring leading to backside leakage",
"Wet clean carry-over or poor DI purge",
],
"process_impacts": {
"Etch": ["Micro-masking causing incomplete etch", "Random shorts"],
"CVD": ["Voids or seams due to nucleation on particles"],
"Lithography": ["Resist bridging, pattern collapse"],
},
"recommended_actions": [
"Run chamber clean recipe and verify seasoning wafers",
"Inspect and replace shields, focus rings, O-rings",
"Tighten pre-clean and FOUP purge; increase post-CMP megasonic",
],
},
"SCRATCH": {
"description": "Mechanical damage on wafer surface",
"likely_causes": [
"Robot end-effector misalignment",
"Carrier/FOUP particle buildup",
"Improper brush pressure in post-CMP clean",
],
"process_impacts": {
"CMP": ["Copper dishing, oxide erosion"],
"Lithography": ["Focus error due to topography"],
},
"recommended_actions": [
"Recalibrate robot path and check edge-grip pads",
"Clean/replace carriers; inspect loadport rollers",
"Lower brush pressure; verify DI flow and spin-dry speed",
],
},
"PATTERN_DEFECT": {
"description": "Pattern fidelity loss or bridging",
"likely_causes": [
"Resist footing from low post-exposure bake",
"Dose drift in scanner",
"Reticle contamination or pellicle damage",
],
"process_impacts": {
"Lithography": ["CD non-uniformity", "Bridges in dense areas"],
"Etch": ["Micro-trenching from resist footing"],
},
"recommended_actions": [
"Re-center dose/focus, run focus-exposure matrix",
"Clean reticle and inspect pellicle for haze",
"Tighten PEB temperature control and bake time",
],
},
"CD_VARIATION": {
"description": "Critical dimension variation across wafer/lot",
"likely_causes": [
"RF power drift or matching network instability",
"Gas MFC offset causing skew",
"Lens heating or stage leveling drift",
],
"process_impacts": {
"Etch": ["CD shrink at edge", "Sidewall angle variation"],
"Lithography": ["Across-wafer CD swing"],
},
"recommended_actions": [
"Re-tune RF matching; verify auto-match recipes",
"Re-zero MFCs and verify calibration logs",
"Run leveling calibration and dose mapper",
],
},
"OVERLAY_ERROR": {
"description": "Layer-to-layer misalignment",
"likely_causes": [
"Stage thermal drift",
"Chuck vacuum instability",
"Incorrect W2W alignment model",
],
"process_impacts": {
"Lithography": ["Overlay shift > spec", "Field rotation"],
},
"recommended_actions": [
"Stabilize stage temp; extend soak time",
"Check chuck vacuum map and backside helium leak",
"Rebuild alignment model with fresh targets",
],
},
}
def _days_ago(days: int) -> str:
return (datetime.utcnow() - timedelta(days=days)).strftime("%Y-%m-%d")
DEFECT_HISTORY: List[Dict] = [
{
"defect_type": "PARTICLE",
"date": _days_ago(3),
"process_step": "Etch",
"equipment_id": "ETCH-01",
"action": "Chamber clean + shield swap; particle adders reduced 80%",
},
{
"defect_type": "SCRATCH",
"date": _days_ago(10),
"process_step": "CMP",
"equipment_id": "CMP-01",
"action": "Robot recalibration; replaced worn end-effector pads",
},
{
"defect_type": "CD_VARIATION",
"date": _days_ago(15),
"process_step": "Lithography",
"equipment_id": "LITHO-03",
"action": "Dose mapper re-center; lens heating compensator enabled",
},
{
"defect_type": "PATTERN_DEFECT",
"date": _days_ago(20),
"process_step": "Lithography",
"equipment_id": "LITHO-02",
"action": "Reticle clean; PEB temp PID re-tuned",
},
{
"defect_type": "OVERLAY_ERROR",
"date": _days_ago(25),
"process_step": "Lithography",
"equipment_id": "LITHO-03",
"action": "Rebuilt W2W alignment model; chuck vacuum leak fixed",
},
]
