Electrical Characteristics Of Charge Trap Flash Memory With A Composition Modulated (Zro2)(X)(Al2o3)(1-X) Film

This research proposes the use of a composition modulated (ZrO2)(x)(Al2O3)(1-x) film as a charge trapping layer for charge trap flash memory; this is possible when the Zr (Al) atomic percent is controlled to form a variable bandgap as identified by the valence band offsets and electron energy loss spectrum measurements. Compared to memory devices with uniform compositional (ZrO2)(0.1)(Al2O3)(0.9) or a (ZrO2)(0.92)(Al2O3)(0.08) trapping layer, the memory device using the composition modulated (ZrO2)(x)(Al2O3)(1-x) as the charge trapping layer exhibits a larger memory window (6.0 V) at the gate sweeping voltage of +/- 8 V, improved data retention, and significantly faster program/erase speed. Improvements of the memory characteristics are attributed to the special energy band alignments resulting from non-uniform distribution of elemental composition. These results indicate that the composition modulated (ZrO2)(x)(Al2O3)(1-x) film is a promising candidate for future nonvolatile memory device applications.