Semi E98

SEMI E98 defines the Object-Based Equipment Model (OBEM) — an alternative to GEM's traditional flat state/event model that represents a tool's components, modules, and sub-processes as a hierarchy of discrete objects, each with its own state and events, so a host can address a specific chamber or module directly rather than inferring its status from the tool's single overall state. GEM's classic state model works well for simpler tools with one process state to report, but a cluster tool with multiple independent process chambers, each running its own recipe on its own schedule, doesn't fit that flat model cleanly — OBEM is the alternative framework that lets each chamber be its own addressable object with its own state machine, nested inside the tool's overall object hierarchy.

Multi-chamber cluster tool, each chamber on its own schedule
GEM's flat single-state model can't represent this cleanly
SEMI E98 — Object-Based Equipment ModelEach component is its own addressable object with its own state
Chamber A — its own state, its own events
Independent of what Chamber B or C are doing
Chamber B — its own state, its own events
Addressed directly, not inferred from tool-level status
Host queries and controls each chamber independently
Accurate per-module status for complex, multi-process tools

The reason OBEM exists as an alternative rather than a replacement for GEM's flat model is that forcing a complex, multi-chamber tool into one overall state inevitably loses information — a tool reporting "processing" tells a host nothing about which specific chamber is actually running, which is idle, and which might be faulted, and a host that needs per-chamber scheduling or diagnostic granularity simply can't get it from a single flat state. OBEM solves this by modeling the tool's internal structure explicitly as nested objects, each independently addressable, which matters most for exactly the equipment types that have proliferated as process complexity increased — cluster tools, multi-station deposition and etch systems, anything where "what is the tool doing" is really several simultaneous, independent answers rather than one.

SEMI E98 — Flat State vs. Object Hierarchy one overall status vs. independently addressable components GEM flat model Tool state: "Processing" Which chamber? Unknown. Any faulted? Unknown. E98 object hierarchy Chamber A: Processing (recipe 3) Chamber B: Idle Chamber C: Faulted Each addressable independently Not a GEM replacement — the alternative for structurally complex tools

E98 is the equipment model that scales with process complexity rather than against it: as tools pack more independent chambers and sub-processes into one footprint, OBEM's object hierarchy is what keeps per-module visibility intact instead of collapsing back into one ambiguous overall status.

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