Internal Power Net Defect Localization Via Holistic Fault Isolation With FIB Edit Pico Probe

Abstract

Effective test coverage served as a gate keeper for device failure screening, this is to ensure none of the failing part escaped to customer side. Samples that failed electrically be means in class test and reliability stress test will need failure analysis for defect root causing. This is crucial for continuous product quality improvement. Physical defect localization to enable defect finding highly depends on optical fault isolation (FI) for defect localization and physical failure analysis (PFA) techniques ranging from sample delayering, secondary electron microscope (SEM) imaging and transmission electron microscopy (TEM) to reveal the physical defect. In certain cases where the failure is suspected to be internal regulated power line induced the section on area for SEM will be much too large. Extensive nano probing is required to isolate the failing region. This along with FIB edit and pico probe will be able to provide electrical failure correlation and to create a hypothesis. In this work, a complete failure analysis fault isolation (FAFI) method using the afore mentioned techniques to lock down the physical defect caused by power rail short reported in power-up-power-down (PUSPDS) test is presented.