HfON/LaON as charge-trapping layer for nonvolatile memory applications

The charge-trapping characteristics of HfON/LaON composite film (denoted as HfLaON) were investigated based on an Al/Al 2 O 3 /HfLaON/SiO 2 /Si (MONOS) capacitor. The physical properties of the high-k film were analyzed by transmission electron microscopy and electron diffraction spectroscopy. Compared with another MONOS capacitor with nitrided La 2 O 3 as charge-trapping layer, the one with HfLaON showed better memory characteristics in terms of larger memory window, higher program speed (6.3 V at +14 V for 100 µs), and smaller charge loss (8.2% after 104 sec), due to the HfLaON composite film exhibiting an amorphous structure and the suppressed formation of an interlayer at the HfLaON/SiO 2 interface.