Formation of CoSi2/CoSixNy Nanocrystals for Nonvolatile Memory Application

Abstract

Nonvolatile nanocrystal memories recently have been one of the promising candidates to replace traditional floating gate nonvolatile memory because the discrete nanocrystal as the charge storage media have effectively improved data retention under endurance test for the device scaling down. In this study, CoSi2 nanocrystal surrounded with CoSixNy shell structure was proposed by rapid thermal annealing a nitrogen incorporated CoSi layer, which was deposited by sputtering CoSi target in the mixture gas of Ar+N2 or Ar+NH3, to improve data retention. The structures and elements composition of nanocrystal were analyzed by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), and the electrical characteristics of nanocrystals memories were defined by C-V curves. Because of the extra CoSixNy shell, the proposed memory can exhibit good data retention to 10 years.