Semi E90

SEMI E90 defines Substrate Tracking, the standard data model that lets GEM-compliant equipment report exactly which physical wafer is in which physical location inside the tool, and what state that wafer is currently in — at a level of detail finer than "the carrier arrived" or "the carrier departed," which is all Carrier Management (SEMI E87) by itself can tell a host. E87 tracks the carrier as a unit moving in and out of a load port; E90 picks up once wafers are actually removed from that carrier and starts tracking each individual substrate's location — a chamber, a load lock, a buffer station, an end-effector — and its processing state, as it moves through the tool's internal wafer-handling system.

Carrier arrives, wafers still inside
Tracked as a unit — SEMI E87 Carrier Management scope
SEMI E90 substrate-tracking scope beginsPer-wafer location and state, not per-carrier
Wafer removed, location updated
Load lock, buffer, chamber, or end-effector
Wafer state updated
WaitingForProcess, InProcess, ProcessComplete, etc.
↻ each internal wafer move
Host always knows exact wafer location + state
Even mid-recipe, across multiple chambers

Substrate tracking matters most exactly when things go wrong, since a tool that can report "wafer 7 is in chamber B, state InProcess" the instant an alarm fires lets a host immediately know which specific wafers need to be quarantined, reprocessed, or scrapped — without E90, an equipment fault would only tell the host that *something* in the tool is wrong, forcing a far more conservative response like quarantining the tool's entire in-progress lot rather than just the wafers actually affected. This per-substrate resolution is also what makes cluster tools with multiple parallel chambers practical to operate under full host supervision at all, since a five-chamber cluster tool processing five different wafers simultaneously has no other standardized way to tell the host which wafer is sitting where at any given moment.

SEMI E90 — Per-Substrate Location Tracking host knows which specific wafer is where, inside a multi-chamber tool Cluster tool mainframe Load lock Wafer 3 Chamber A Wafer 1 — InProcess Chamber B Wafer 2 — ALARM Buffer station Wafer 4 — Waiting Wafer 5 — on robot arm Only Wafer 2 needs quarantine — not the whole lot possible only because E90 tracks location and state per individual substrate

SEMI E90 is what turns the carrier-level visibility of E87 into wafer-level visibility once substrates leave the carrier, and it is the data foundation that higher-level standards like Control-Job Management (E94) and Module Process Tracking (E157) build on to coordinate processing across multiple chambers and multiple wafers at once.

Take SEMI E90 further

Ask the copilot about this term, or have our engineers assess it against your process.

Ask CFSGPT about this → Request a technical assessment → Open the CFS app