Flash memory based on solution processed hafnium dioxide charge trapping layer†
Hafnium dioxide (HfO2) film prepared by the sol–gel technique has been used as a charge trapping layer in organic flash memory. The thickness, crystallinity and morphology of HfO2 fabricated under various conditions were investigated. X-ray diffraction (XRD) patterns indicated the formation of monoclinic HfO2 crystals with increasing annealing temperature. Atomic force microscopy (AFM) images showed relatively smooth films of HfO2 growth. The annealing temperature-dependent effects on the memory window as well as data retention properties have been discussed. A large memory window and long data retention time have been achieved for the pentacene-based flash memory. The results demonstrate that solution processed HfO2 film could be a promising candidate as a charge trapping layer in printable flash memory.