Nonvolatile nanocrystal charge trap flash memory devices using a micellar route to ordered arrays of cobalt nanocrystals

Abstract

This study demonstrates that self-assembled diblock copolymer micelles can be used as a template to assemble cobalt (Co) nanocrystal (NC) arrays for use as charge storage layers in charge trap flash memory devices. Diblock copolymer micelles embedded with Co were synthesized on p-Si substrates having a thin tunneling oxide of HfO2. The micelle templates were completely removed by oxygen plasma treatment and reduction procedures, resulting in ordered arrays of Co NCs. The nonvolatile memory devices exhibit program/erase characteristics, as confirmed by their capacitance-voltage responses, current-voltage responses, endurance characterization, and nanoscale device measurement using scanning nonlinear dielectric microscopy.