Comparison of reliability of single and stacked high-k structures of charge trapping memories

High-k dielectrics are candidate materials for the charge trapping layer of charge trapping memory devices. The use of this material allows to obtain a larger memory window and better retention performance. We investigate charge trapping memory capacitors with single or stacked high-K structures. Improved memory windows can be achieved by adopting stacked high-k films as charge trapping layers. However, the data retention characteristics of stacked structures are degraded with respect to the ones of single-layer high-k structures.