Effect of (HfO_2)_X(Al_2O_3)_(1-X)/SiO_2 double-layered blocking oxide on program and erase speed in charge trapping memory devices

摘要

In this work, the effect of hole injection into the charge trap layers from channel prior to program operation is investigated in charge trapping (CT) memory with stacked blocking oxide (BO). For efficient hole injection, a (HfO_2)_x(-Al_2O_3)(1-X)/SiO_2 stacked BO structure is used. The CT memory device with stacked BO shows faster programming and erasing speed compared with single-layered SiO_2 BO. The enhanced programming speed is attributed to the enhanced electric field introduced by excess holes injected into SiN charge trap layer. In addition, efficient hole injection from channel produced the widened memory window in CT memory.