Dynamic flash memory (dfm) with ring-type insulator in channel for improved retention

Abstract

A three-dimensional (3D) memory device includes a memory cell, a top contact coupled to the memory cell, and a bottom contact coupled to the memory cell. The memory cell can include a pillar, an insulating layer surrounding the pillar, a first gate contact coupled to a word line, a second gate contact coupled to a plate line, and an annular dielectric layer within a portion of the pillar. The annular dielectric layer can increase a retention time of electrical charge in the pillar. The 3D memory device can utilize dynamic flash memory (DFM), increase retention times, decrease refresh rates, increase a floating body effect, decrease manufacturing defects, decrease leakage current, decrease junction current, decrease power consumption, increase an upper limit of charge density in the pillar, dynamically adjust a length of the plate line, and decrease parasitic resistance.