barcode scanner

Barcode scanners read **printed or laser-scribed identification codes** on wafers, lots, cassettes, and FOUPs for tracking and traceability throughout semiconductor manufacturing. **Barcode Types in Fabs** **1D Barcodes** are traditional linear barcodes on lot travelers, cassettes, and chemical containers. **2D Matrix (Data Matrix)** codes are laser-scribed on wafer backsides, encoding wafer ID in a small dot pattern that remains readable even after processing. **OCR (Optical Character Recognition)** reads human-readable text alongside barcodes for redundancy. **Where Scanners Are Used** **Lot tracking** scans lot ID at each process step for MES tracking and history. **Wafer-level ID** uses backside 2D matrix codes to identify individual wafers within a lot, read by specialized wafer readers at key process points. **Chemical management** scans container barcodes to verify correct chemistry is loaded in wet benches. **Reticle management** reads reticle barcodes to confirm the correct mask is loaded in lithography tools. **Scanner Types** **Handheld scanners**: Operators scan lot travelers manually at non-automated tools. **Fixed-mount scanners**: Permanently installed at tool load ports for automatic reading. **Wafer readers**: Specialized equipment reads laser-scribed 2D codes on wafer backsides through FOUP windows or at prealign stations. **Integration** Scanners connect to MES via serial or network interface. Each scan event updates lot location and triggers recipe download or dispatch instructions.