stuck-at fault

**Stuck-at fault** is **a structural fault model where a signal line is assumed permanently fixed at logic zero or logic one** - Test vectors are generated to activate and propagate the assumed stuck condition to observable outputs. **What Is Stuck-at fault?** - **Definition**: A structural fault model where a signal line is assumed permanently fixed at logic zero or logic one. - **Core Mechanism**: Test vectors are generated to activate and propagate the assumed stuck condition to observable outputs. - **Operational Scope**: It is used in semiconductor test and failure-analysis engineering to improve defect detection, localization quality, and production reliability. - **Failure Modes**: Exclusive reliance on stuck-at modeling can miss delay and analog-sensitive defects. **Why Stuck-at fault Matters** - **Test Quality**: Better DFT and analysis methods improve true defect detection and reduce escapes. - **Operational Efficiency**: Effective workflows shorten debug cycles and reduce costly retest loops. - **Risk Control**: Structured diagnostics lower false fails and improve root-cause confidence. - **Manufacturing Reliability**: Robust methods increase repeatability across tools, lots, and operating corners. - **Scalable Execution**: Well-calibrated techniques support high-volume deployment with stable outcomes. **How It Is Used in Practice** - **Method Selection**: Choose methods based on defect type, access constraints, and throughput requirements. - **Calibration**: Use stuck-at coverage with complementary fault models such as transition and bridging. - **Validation**: Track coverage, localization precision, repeatability, and field-correlation metrics across releases. Stuck-at fault is **a high-impact practice for dependable semiconductor test and failure-analysis operations** - It provides a simple and widely used baseline for digital structural testing.