Lot Tracking

Lot tracking is the end-to-end recording of each wafer lot's location, process history, status, and genealogy across the manufacturing lifecycle - it provides the operational visibility required for quality control and delivery management.

What Is Lot tracking?

• Definition: Continuous monitoring of lot movement and process events from start to completion.
• Core Elements: Route step, tool history, timestamps, holds, merges, splits, and ownership status.
• System Backbone: Managed primarily through MES with interfaces to AMHS and equipment automation.
• Traceability Scope: Includes parent-child genealogy when lots are split, merged, or reworked.

Why Lot tracking Matters

• Quality Investigation: Enables rapid backward and forward trace during excursions.
• Schedule Control: Accurate lot status is essential for dispatch and due-date management.
• Compliance Assurance: Supports auditable chain-of-custody for regulated and customer-critical products.
• Cycle-Time Reduction: Eliminates time lost searching for lot location and state.
• Risk Containment: Helps isolate affected product quickly during tool or material events.

How It Is Used in Practice

• Event Capture: Log every process and transport transition with precise timestamps.
• Genealogy Management: Maintain explicit links for split, merge, and rework operations.
• Dashboard Control: Provide real-time lot-location and risk-state visibility to operations teams.

Lot tracking is a fundamental digital control capability in semiconductor manufacturing - accurate lot history and real-time location visibility are critical for quality assurance, planning accuracy, and rapid incident response.