Charge-trapping characteristics of BaTiO3 with and without nitridation for nonvolatile memory applications

• Charge-trapping characteristics of nitrided BaTiO3 have been investigated by comparison with pure BaTiO3.
• Low operating voltage as well as high operating speeds can be achieved for both of the devices.
• The device with nitrided BaTiO3 as charge-trapping layer shows better performance than the one with pure BaTiO3.

The charge-trapping characteristics of BaTiO3 with and without nitrogen incorporation were investigated based on Al/Al2O3/BaTiO3/SiO2/Si (MONOS) capacitors. The physical properties of the high-k films were analyzed by transmission electron microscopy and X-ray photoelectron spectroscopy. Compared with the MONOS capacitor with BaTiO3 as charge-trapping layer, the one with nitrided BaTiO3 showed higher program speed even at lower operating voltage (4.3 V at +8 V for 100 μs), better endurance property and smaller charge loss (charge loss of 10.6% after 104 s at 85 °C), due to the nitrided BaTiO3 film exhibiting higher charge-trapping efficiency caused by nitrogen incorporation and suppressed leakage induced by nitrogen passivation.