Gate Bias Dependence of Complex Random Telegraph Noise Behavior in 65-nm NOR Flash Memory

The dependence of complex random telegraph noise (RTN) behavior on gate bias is investigated. Noise-type transition among 1/f noise, two-level RTN, and three-level RTN is observed depending on the gate bias. The transition can be detected in both program and erase states and the corresponding transition voltage decreases with the increase of threshold voltage. The phenomena are interpreted by the spectroscopic analysis of process-induced trap and stress-induced trap. A three regions model is finally proposed.