Improved charge-trapping properties of HfYON film for nonvolatile memory applications in comparison with HfON and Y2O3 films

The charge-trapping properties of HfYON film are investigated by using the Al/HfYON/SiO2/Si structure. The physical features of this film were explored by transmission electron microscopy and x-ray photoelectron spectroscopy. The proposed device shows better charge-trapping characteristics than samples with HfON or Y2O3 as the charge-trapping layer due to its higher trapping efficiency, as confirmed by extracting their charge-trap centroid and charge-trap density. Moreover, the Al/Al2O3/HfYON/SiO2/Si structure shows high program speed (4.5 V at +14 V, 1 ms), large memory window (6.0 V at ±14 V, 1 s), and good retention property, further demonstrating that HfYON is a promising candidate as the charge-trapping layer for nonvolatile memory applications.