Engineering the complete MANOS-type NVM stack for best in class retention performance

We demonstrate best in class performance for MANOS-type charge-trap flash non-volatile memory devices through improved program/erase (P/E), endurance and retention. Band-engineered (BE) tunnel-oxides (TO) and BE-SiN_x charge-trap layers are employed to optimize program, erase, and endurance with trade-off in retention. However, for the 1st time we combine BE-TO, BE-SiN_x, BE-blocking layer (BE-BL) and an oxygen-bearing high effective-work-function (EWF) electrode to dramatically improve retention while maintaining the combined benefits from the engineering of each individual stack component. Resulting device improvements include larger ¿Vth P/E windows of > 300%, enduring P/E cycles to at least 100 K cycles while maintaining a window > 4 V, and retention approaching zero% charge loss over 24 hours at 150°C. The large, enduring windows with improved retention are favorable for multi-level cell application beyond the 30 nm node.