Improved Memory Characteristics by NH3Post Annealing for ZrO2Based Charge Trapping Nonvolatile Memory

Abstract

Charge trapping nonvolatile memory capacitors with <TEX>$ZrO_2$</TEX> as charge trapping layer were fabricated, and the effects of post annealing atmosphere (<TEX>$NH_3$</TEX> and <TEX>$N_2$</TEX>) on their memory storage characteristics were investigated. It was found that the memory windows were improved, after annealing treatment. The memory capacitor after <TEX>$NH_3$</TEX> annealing treatment exhibited the best electrical characteristics, with a 6.8 V memory window, a lower charge loss ~22.3% up to ten years, even at <TEX>$150^{\circ}C$</TEX>, and excellent endurance (1.5% memory window degradation). The results are attributed to deep level bulk charge traps, induced by using <TEX>$NH_3$</TEX> annealing.