Electrical characteristics of a ZrO2/SiO2 modified tunnel barrier for low-temperature non-volatile memory

The electrical characteristics of nonvolatile memory, which consists of an asymmetrical ZrO₂/SiO₂ (ZO) modified tunnel barrier, a high-k HfO₂ trapping layer and an Al₂O₃ blocking layer, were investigated for the application of a tunnel barrier engineered nonvolatile memory at low process temperatures. The efficiency of the ZO modified tunnel barrier on the charge trap flash (CTF) memory cell was compared to a conventional single SiO₂ tunnel barrier. The ZO tunnel barrier revealed field sensitivity larger than the single SiO₂ tunnel barrier. The programming and erasing speeds as well as the retention and endurance characteristics of CTF memory were largely enhanced. Moreover, the forming gas annealing process in 2% diluted H₂/N₂ ambient improved the charging trapping property and tunneling sensitivity of the ZO modified tunnel barrier.