Three walk-throughs. All of them labelled scenarios.
Waferira has no customer results yet, so this page does not pretend to. Each scenario describes a hypothetical module, what the agent would do at each autonomy level, and the metric table the pilot would fill in. When a design partner signs, the first real case study replaces the first scenario.
Illustrative scenario: Module M2 · 300 mm · metal-1 · lot L-48213, one lot through metal-1, one approval gate
Dispositioning defects and catching the excursion inline
A hypothetical inspection cell on a logic fab's metal layers: one inline optical tool, one e-beam review tool and SEM review, generating more images per shift than the defect team can open. Today killer and nuisance are separated by hand and a reticle repeater is found at final test.
What the agent would do
- Shadow mode. Scanira fuses the three modalities at the tool edge, classifies every event and scores excursion risk, writing nothing and raising no holds.
- Assist mode. Scanira proposes killer-or-nuisance dispositions and inline holds; the defect engineer approves each one and corrections train the classifier.
- Bounded autonomy. nuisance dispositions and increased sampling execute automatically; reticle and pattern holds go through the named approver with the OCAP linked.
| Metric | How | Result |
|---|---|---|
| Review load | defect-review hours per week, before and during | to be measured |
| Excursion catch | excursions found inline rather than at later metrology or test | to be measured |
| Classification accuracy | against engineer labels on a held-out set | to be measured |
| Scrap | lots scrapped or reworked per excursion | to be measured |
No result is claimed. The metric table is what the pilot would record.
Closing run-to-run overlay and CD control with virtual metrology
A hypothetical litho cell with one scanner, sampled overlay and CD metrology and an existing APC system. Correctables are updated after sampled measurements, so a residual trend can reach the control limit a lot too late.
What the agent would do
- Shadow mode. Lithera predicts overlay and CD response per field and layer from the metrology trend and Scanira defect signals; Vmetra scores every wafer at post-etch to close the gap between samples.
- Assist mode. Lithera proposes per-field correctables and focus-dose trims; the litho engineer approves each one and the twin's prediction is checked against the next measurement.
- Bounded autonomy. correctable updates inside the qualified window execute automatically; any out-of-window move waits for the named approver.
| Metric | How | Result |
|---|---|---|
| Overlay residual | nm, predicted and measured, per layer | to be measured |
| CD uniformity | across-wafer, per lot | to be measured |
| Lot scrap at litho | lots scrapped or reworked, before and during | to be measured |
| Metrology sampling | wafers measured physically per lot | to be measured |
No result is claimed. The metric table is what the pilot would record.
Holding uniformity between measurements
A hypothetical etch module and CMP module on a memory fab's long flow, with FDC on every chamber and physical metrology sampled. Uniformity drifts between samples and surfaces as an excursion after the wafers have moved on.
What the agent would do
- Shadow mode. Vmetra predicts film thickness, uniformity and removal rate from FDC signatures on every wafer and compares them against the sampled metrology.
- Assist mode. Vmetra proposes pressure, RF, time and downforce trims inside the qualified window and a predicted-variance sampling plan; the module engineer approves each one.
- Bounded autonomy. in-window trims and sampling routing execute automatically; chamber holds and anything outside the window wait for the named approver.
| Metric | How | Result |
|---|---|---|
| Virtual-metrology error | against physical metrology on sampled wafers | to be measured |
| Excursions caught | before physical metrology, per quarter | to be measured |
| Metrology sampling | wafers measured per lot, before and during | to be measured |
| Post-CMP thickness variance | per lot, before and during | to be measured |
No result is claimed. The metric table is what the pilot would record.
The reference scenario, step by step
Every Waferira run is an ordered, inspectable sequence. This is run_7b2e9c on Module M2 · 300 mm · metal-1 · lot L-48213. Scenario completes in 10 steps with one approval gate. Overlay and CD predicted inside spec, one reticle-repeater signature caught and held for review, dispatch re-optimised, lot released with full genealogy.
-
01
ingest.lot
SUCCEEDED
0.7 s
Fab Orchestrator · Pulled lot L-48213 from fab MES: 25 wafers, 300 mm, metal-1 layer, route, reticle, overlay and CD spec and the standing cycle-time target. Locked the target envelope for the run.
-
02
twin.simulate
SUCCEEDED
38 s
Fab Twin · Simulated 64 candidate correctable, recipe and dispatch sets on the as-run fab twin and ranked them on predicted overlay residual, CD uniformity, excursion risk and cycle time.
-
03
litho.correctables
SUCCEEDED
1 m 20 s
Litho-and-Overlay · Per-field overlay correctables and a focus-dose trim written to scanner SCN-07 over SECS/GEM after the previous lot's residual trended toward the control limit. Predicted overlay residual back inside spec.
-
04
etch.uniformity
SUCCEEDED
58 s
Etch-and-Depo · Chamber B on etcher ETCH-12 showed an edge-fast uniformity drift in FDC. Pressure and RF trims written within the qualified recipe window; predicted CD uniformity recovered.
-
05
cmp.removal
SUCCEEDED
46 s
CMP-and-Implant · Downforce and platen-speed trim on CMP-03 against the virtual removal-rate estimate to hold post-CMP thickness and dishing inside the window.
-
06
inspect.classify
SUCCEEDED
continuous
Defect-and-Inspect · Inline optical, e-beam review and SEM imagery fused at the tool edge. 1,412 events classified, most dispositioned nuisance; one reticle-repeater signature on three dies flagged for review.
-
07
vm.score
SUCCEEDED
2.1 s
Metrology-and-Virtual · Virtual metrology scored every wafer at post-etch and post-CMP from tool-sensor and FDC signatures. Two wafers routed to physical metrology on predicted variance; the rest sampled at plan.
-
08
approve.human
APPROVAL
1 m 04 s
Fab Orchestrator · The reticle-repeater signature called for a reticle inspection hold and a recipe move outside the qualified window. Held for the module process engineer and approved at 03:14:27.
-
09
dispatch.route
SUCCEEDED
4.3 s
Yield-and-Dispatch · Dispatch re-optimised across 1,840 lots in WIP under reticle, chamber and qualification constraints. The lot routed to the qualified chamber with the shortest predicted queue; AMHS move issued to the stocker.
-
10
lot.release
SUCCEEDED
1 m 05 s
Quality-and-Conformance · Lot L-48213 moved on: genealogy written (recipe moves, correctables, FDC signatures, VM scores, defect map, approvals) and checked against the layer spec.
The agent shows its work
Every tool invocation, argument and result is written to an append-only, IP-isolated, human-readable log, and every reasoning step is expandable. Nothing about a run is hidden from the fab.
- 03:02:10mes.read_lot({ lot: "L-48213", layer: "M1", module: "M2" })
- 03:02:11ok 25 wafers · reticle R-M1-114 · overlay and CD spec locked
- 03:02:11twin.simulate({ candidates: 64, horizon: "lot" })
- 03:02:49ok best set #41 · overlay residual 2.6 nm · excursion risk 0.05
- 03:02:50policy.evaluate({ set: 41, autonomy: "L3" })
- 03:02:50ok 7 recipe writes inside qualified window · 1 move requires human approval
- 03:02:51secs.write_recipe({ tool: "SCN-07", correctables: "per_field", dose: "-0.3%" })
- 03:04:11ok predicted overlay residual 3.1 → 2.6 nm · CD on target
- 03:04:12secs.write_recipe({ tool: "ETCH-12", chamber: "B", pressure: "+1.5%", rf: "-0.8%" })
- 03:05:10ok edge-fast drift cleared · predicted uniformity inside window
- 03:05:11secs.write_recipe({ tool: "CMP-03", downforce: "-2%", platen: "+1%" })
- 03:05:57ok virtual removal rate on target · dishing inside window
- 03:05:58vision.stream({ tools: ["INS-02", "EB-01", "SEM-04"] })
- 03:09:40repeater: 3 dies · same field position · reticle R-M1-114 · killer class
- 03:09:41vm.predict({ lot: "L-48213", steps: ["post_etch", "post_cmp"] })
- 03:09:43ok 25 wafers scored · 2 routed to physical metrology
- 03:09:44approval.request({ action: "reticle_hold", recipe_move: "outside_window" })
- 03:14:27ok approved by module process engineer · OCAP linked · logged
- 03:14:28cuopt.dispatch({ wip: 1840, constraints: ["reticle", "chamber", "qual"] })
- 03:14:32ok lot routed to ETCH-12/B · AMHS move to stocker ST-14
- 03:14:33amhs.move({ foup: "F-20911", to: "ST-14" })
- 03:15:21ok carrier delivered · handling exceptions 0
- 03:15:22mes.log_lot({ lot: "L-48213", genealogy: "full" })
- 03:16:27ok scenario complete · 10 steps · 1 hold reviewed · released
Reasoning trace
Plan, thought, action, observation, exactly as the orchestrator would record it.
GoalRun lot L-48213 through metal-1 on module M2, hold overlay and…
Run lot L-48213 through metal-1 on module M2, hold overlay and CD inside the layer spec, catch any excursion before physical metrology, and dispatch on cycle-time target.
PlanSimulate the lot on the twin first. Lead with litho so the cor…
Simulate the lot on the twin first. Lead with litho so the correctables are right before etch, then trim etch and CMP against virtual metrology, keep inspection continuous, and hold anything outside the qualified window for a human.
ThoughtThe previous lot's overlay residual on SCN-07 trended toward t…
The previous lot's overlay residual on SCN-07 trended toward the control limit. On the twin, a per-field correctable update with a small dose trim brings the predicted residual back to 2.6 nm without touching focus.
Actiontwin.simulate(candidates=64) returns set #41: per-field correc…
twin.simulate(candidates=64) returns set #41: per-field correctables and dose minus 0.3% on SCN-07, chamber B pressure and RF trims on ETCH-12, downforce minus 2% on CMP-03.
ObservationSet #41 predicts overlay residual 2.6 nm, CD uniformity inside…
Set #41 predicts overlay residual 2.6 nm, CD uniformity inside window and excursion risk 0.05. Nine candidates cut cycle time further but routed the lot to an unqualified chamber and were discarded.
ActionExecute set #41 under autonomy level L3: seven recipe writes i…
Execute set #41 under autonomy level L3: seven recipe writes inside the qualified window, the reticle hold and the out-of-window move routed to the module process engineer.
ObservationReticle-repeater signature on three dies at 03:09:40 from the …
Reticle-repeater signature on three dies at 03:09:40 from the fused inspection stream. Virtual metrology routed two wafers to physical measurement on predicted variance.
OutcomeScenario complete. Overlay and CD predicted inside spec, the r…
Scenario complete. Overlay and CD predicted inside spec, the repeater held and reviewed with the OCAP linked, the lot dispatched to a qualified chamber and released with full genealogy.
Four levels, set per agent and per tool
A fab does not go from manual APC to unattended control in one step. Waferira makes the level explicit, auditable and reversible at any time. The first release runs shadow mode, then assist mode, then graduated autonomy for low-risk APC, defect and metrology loops.
| Level | What the agent does | What the human does | Where it sits in a pilot |
|---|---|---|---|
| L1 · Advisory | Recommends recipe moves, dispositions and dispatch, with citations | Enters every change manually | Shadow mode, first on the design-partner cell |
| L2 · Supervised | Proposes a recipe write or hold; it executes on approval | Approves each move in the review console | Assist mode, where accuracy and ROI are proven |
| L3 · Bounded | Writes inside the qualified recipe window, tool-state checks and OCAP linkage | Approves holds, out-of-window moves and lot release | Graduated autonomy for low-risk APC, defect and metrology loops |
| L4 · Qualified loops | Runs a qualified loop without prompting, inside its envelope | Sets the envelope; reviews the shift record | Planned; reserved for loops the fab has qualified |
Straight answers
The questions fab directors and process engineers ask in the first meeting.
Yes, over SECS/GEM, but only inside the qualified recipe window for that tool, with per-parameter limits and tool-state checks, and only at the autonomy level your fab has set. Level 1 is advisory: Waferira recommends and an engineer enters everything. Design partners start there, in shadow mode.
The tool stays on its own controller and its last qualified recipe. Waferira is a supervisory layer on top of the APC, inspection, metrology and MES systems you already run, never a replacement for them, so an outage leaves the module running the way it runs today.
No. Inference and feature storage stay at the fab edge, recipes, device designs, defect libraries and process memory are isolated per tenant, and an on-prem control plane is available for IP-sensitive fabs. Any cross-fab learning is planned, contract-gated and privacy-preserving, and none of it moves recipes or designs.
Advisory recommendations start from the existing APC, metrology and ADC data on the wedge module. Defect classification, virtual metrology and excursion prediction improve as labelled events and lot outcomes accumulate per process family. Rare excursions are augmented synthetically only after validation against real distributions.
You are, the same as with any APC strategy, which is why every write is policy-checked, bounded to the qualified window, logged and reversible, and why holds, out-of-window moves and lot release wait for a named approver with the OCAP linked.
A paid pilot on one process module or tool fleet, scoped to one wedge workflow with a baseline agreed in writing. Shadow mode first, observing and measuring the baseline. Then assist mode, where the agent recommends and your engineer approves and accuracy and ROI are measured. Then bounded autonomy for low-risk APC, defect or metrology loops if the fab is satisfied.
Make the first scenario real
Start with one process module or tool fleet and one measurable baseline. A paid, IP-isolated pilot on defect classification, virtual-metrology-driven overlay and CD control or uniformity APC shows the number before you commit further.