Failure Analysis Case Study in 0.18μm Flash Memory Devices and Root Cause Identification

This report summarizes the analysis of 0.18µm Flash ROM technology qualification failure cases at Macronix. The cases include single cell read failures, erase/program function failures, and high temperature storage test failures. Electrical analysis, EMMI and physical check by chemical de-processing, parallel lapping, FIB, SEM, PVC and TEM techniques were employed to identify the failure mechanisms, root causes, and solutions. From this study, improvements were achieved in process defect density, test fault coverage and product reliability of the 0.18µm Flash ROM technology.