The Study of High-k ZrO2 and Ti-doped Nb2O5 Charge Trapping Layers for Nonvolatile Memory Application

• Main Authors: Chih Ju Lin, 林志儒
• Other Authors: C. H. Kao
• Format: Others
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/74132815863754367339

碩士 === 長庚大學 === 電子工程學系 === 100 === Recently, the MOHOS-type nonvolatile memory with high-k charge trapping layer was used to replace conventional floating gate memory due to high trap density, thermal stability, large conduction band offset and equivalent oxide thickness (EOT). In this thesis, the high-k ZrO2 materials was used as charge trapping layer in flash memory, the physical and electrical characteristics of ZrO2 in different nitrogen compositions were investigated. According to the result, the memory device using ZrO2 trapping layer with high nitrogen composition can achieve a larger memory window and better charge storage ability. On the other hand, the Nb2O5 and Ti-doped Nb2O5 materials were also used as charge trapping layer in memory devices. It could be found that the Ti-doped Nb2O5 charge trapping layer annealed at 900oC exhibited a larger memory window about 9.35V, faster program/erase speed and better data retention compared with the Nb2O5 trapping layer. Finally, two different thicknesses of 12nm and 18nm Ti-doped Nb2O5 trapping layer were also investigated. It also could be found that the memory device with 18nm TiNb2O7 trapping layer can obtain a larger memory window about 9.66V and faster program/erase speed than that with 12nm trapping layer. Therefore, the developed Ti-doped Nb2O5 can be a very promising charge trapping layer for future memory applications.