Advanced flash memory reliability

With reference to the mainstream technology, the most relevant failure mechanisms that affect reliability of Flash memory are reviewed, showing the primary role played by tunnel oxide defects. The degradation of device performance induced by program/erase cycling is discussed, specifically for what concern the leakage that affect a very small fraction of memory cells after cycling. The dependence of the leakage on tunnel oxide thickness, number of cycles, and temperature is analyzed. The leakage current is explained by trap-assisted tunneling involving one, two or more traps, with decreasing occurrence probability. Finally, data are presented showing the robustness of scaled Flash memory to alpha particles and electromagnetic radiation.