Fault Localization of Temperature-Dependent Digital Circuit Functional Failures Utilizing the Scan-based Bench Testing and the Dynamic Analysis by Laser Simulation (DALS)

Abstract

Soft defect failures are challenging, especially when dealing with the bias condition at the specific failing temperature. Fault localization of temperature-dependent digital circuit functional failures utilizing the scan-based bench Testing and the Dynamic Analysis by Laser Simulation (DALS) will employ a failure analysis flow based on the dynamic power dissipation theory. This study presents an alternative approach to solving temperature-dependent failures using the power dissipation equation by varying variables like voltage supply level and frequency or the speed instead of varying the temperature. The design principles of scan-based testing, which the design engineers utilize during the initial manufacturing phase, were used to solve failures on the digital block. During fault localization, the laser scanning microscope provides a temperature change proportional to the temperature dependency of the failing device. The objective is to bring the device to the failing state whenever the laser scans across the temperature-sensitive area of the die. The study showcases failure analysis cases that showed a significant improvement in the level of the analysis process, a drastic cycle time reduction in the analysis, and an almost 100% success rate in identifying the root cause compared with the conventional analysis.