Influence of RPO Film and CESL Material on Data Retention in Non-Volatile Memory

in this study, we evaluated the effect of resist protection oxide (RPO) and contact etch stop layer (CESL) on the retention characteristics of non-volatile memory (NVM). Based on this comprehensive study, though thicker RPO thickness and NH3-based silicon nitride (SiN) CESL can improve data retention, few samples suffer unexpected large variation issues. These retention behaviors result in unstable data storage performance and potentially lead to product failures and production yield loss. An alternative solution has been explored to improve the data retention characteristic by replacing the NH3-based CESL with N2-based mixing NH3 gas flow. This method successfully demonstrates excellent data retention capability in the actual memory samples.