Core capabilities
- Antenna analysis: Check metal-to-gate area ratios and identify nets that may accumulate charge during fabrication and cause gate-oxide breakdown.
- Metal density analysis: Tile-by-tile checks that metal density meets CMP planarization requirements; outputs density heat maps and violation regions.
- Redundant via analysis: Assess reliability risk of single-via connections and recommend locations for redundant vias.
- Pattern risk detection: Identify layout topologies that may cause lithography/etch yield issues (sharp corners, narrow necks, isolated lines).
- Yield risk scoring: Unlike DRC pass/fail, DFM provides continuous yield risk scores with priority ranking.
Agent calling patterns
dfm = client.call("iDFM.check",
design_ref="snap_7f3a",
checks=["antenna", "density", "via"]
)
# dfm.yield_risks → list[dict] (risk list, priority sorted)
# dfm.risk_scores → dict (per-check risk scores 0-1)
# dfm.recommendations → list[dict] (fix recommendations)
Input / output contract
| Direction | Parameter | Type | Description |
|---|---|---|---|
| Input | design_ref | str | Post-route design snapshot reference |
| Input | checks | list[str] | Check items: antenna, density, via, pattern, cmp |
| Input | tech_config | dict (optional) | Process thresholds: antenna_ratio, density_range, via_cutoff |
| Output | yield_risks | list | Yield risk items: type, location, severity, description |
| Output | risk_scores | dict | Normalized per-dimension risk scores (0-1) and overall composite |
| Output | recommendations | list | Fix recommendations: action, target, expected_yield_gain |
Role in the flow
01 Route
iRT
Global & detailed routing
02 DRC
iDRC
Hard design rule check
03 DFM
iDFM
Yield risk assessment
04 Signoff
iLVS · iSTA
Final signoff (with DFM fixes)
iDFM runs after DRC pass, focusing on yield-related soft checks. DRC ensures the design can be manufactured; DFM ensures high-yield manufacturing. Antenna and density foundations partially exist in iDRC and iRT today.
Related resources
- iDRC — Design rule check: Hard DRC is a prerequisite for DFM; partial antenna/density foundations live here.
- iRT — Global & detailed routing: Redundant via insertion and density optimization can start during routing.
- EDA tools overview: Map of all 22 point tools.