Fab Standards: SECS-II/HSMS and GEM300
Semiconductor fabs require a different level of automation than general manufacturing. A single 300mm wafer line operates hundreds of heterogeneous tools simultaneously — ASML scanners, AMAT etchers, TEL deposition equipment — running 24/7 without interruption. The communication standard between equipment and MES in this environment is SECS/GEM (SEMI Equipment Communications Standard / Generic Equipment Model).
Five Core Standards
SEMI E5 (SECS-II): Message content standard. Defines approximately 200 Stream/Function-based messages such as S1F1 (Are You There) and S6F11 (Event Report)SEMI E37 (HSMS): TCP/IP-based transport layer. Replaces legacy SECS-I (RS-232), uses standard port 5000, Select/Linktest handshakeSEMI E30 (GEM): Equipment behavior model. Defines Control State, Process State, Equipment ConstantsSEMI E40: Process Job management. Standardizes recipe execution units (carrier-level operations)SEMI E90: Substrate Tracking. Per-wafer location and state trackingSEMI E94: Control Job. Bundles multiple Process Jobs for schedulingSEMI E10: Equipment availability classification (Productive/Standby/Engineering/Scheduled Down/Unscheduled Down/Non-Scheduled). The basis for OEE calculationSECS/GEM Advantages Over OPC-UA
OPC-UA is a versatile general-purpose industrial protocol, but lacks standardization for immediate semiconductor fab deployment. SECS/GEM dominates in the following areas.
Recipe Management Standardization: Automated recipe download/upload/delete via PPID (Process Program ID) using S7F1~F19 messagesStandard Event/Alarm Codes: Pre-defined CEID (Collection Event ID) and ALID (Alarm ID) → simplified MES-side parsing logicImmediate Compatibility: Over 95% of global OEM equipment supports SECS/GEM, no custom driver development neededTraceability: Automatic per-wafer history via E90 Substrate TrackingIf OPC-UA is a "communication specification," SECS/GEM is "a standard that includes semiconductor-domain business logic."
MES Integration Architecture
Real-world fab automation consists of a 4-layer data flow.
```
[Equipment PLC/PC] → [EAP] → [MES] → [ERP/EDW]
E37/HSMS SECS-II REST SAP IDoc
```
Equipment Layer: Equipment PC connects to EAP in HSMS-Active/Passive mode. 30-second heartbeatEAP (Equipment Application): Per-equipment SECS/GEM adapter. Message normalization plus business logic (recipe validation, MES communication)MES: Work order issuance, tracking, quality management. Must handle tens of thousands of events per hourERP: Materials, costing, accounting integrationAt a 300mm fab, one EAP typically handles 8-16 tools, with message throughput reaching 500-2000 per second.
POLYGLOTSOFT Integration Case
POLYGLOTSOFT has conducted multiple integration PoCs for backend and OSAT (Outsourced Semiconductor Assembly and Test) lines.
OSAT Packaging Line Integration Case
Equipment Mix: 12 wire bonders, 8 molding tools, 6 laser markers, 20 test handlers (46 total)Prior Problem: Proprietary protocols per tool → manual data entry, 48-hour OEE calculation delayStandards Applied: SECS-II/HSMS plus E10 (availability), E40 (Process Job), E94 (Control Job)Results: Real-time OEE calculation, 1.8% yield improvement, 4 data-entry headcount reductionMigration Checklist
Equipment Inventory: SECS/GEM support status, host IP, port mappingEAP Design: Decide between 1:1 per-equipment mapping or cluster mappingGEM Variable Mapping: Build SVID, ECID, DVID catalogRecipe Migration: Convert file-based recipes to PPID systemTesting: VEY (Equipment Implementation) verification, simulator validation before real wafer runsPhased Rollout: Single-line PoC → line expansion → full fab---
POLYGLOTSOFT is a SEMI-standard-based smart factory integration specialist. We provide full-stack support from SECS/GEM EAP development and MES construction to legacy equipment migration. If you are considering backend/OSAT line automation, start with a PoC through our [subscription development service](/subscription). Free consultation and 24-hour prototyping are available.
