Fabrication and Electrical Characterization of MONOS Memory with Novel High-κ Gate Stack

A novel high-kappa gate stack structure with HfON/SiO2 as dual tunneling layer (DTL), AlN as charge storage layer (CSL) and HfAlO as blocking layer (BL) is proposed to prepare the charge-trapping type of MONOS non-volatile memory device by employing in-situ sputtering method. The memory window, program/erase and retention properties are investigated and compared with similar gate stack structure with Si3N4/SiO2 as DTL, HfO2 as CSL and Al2O3 as BL. Results show a large memory window of 3.55 V at PIE voltage of +8 V/-15 V, high program/erase speed and good retention characteristic can be achieved using the novel Au/HfAlO/AIN/(HfON/SiO2)/Si gate stack structure. The main mechanisms lie in the enhanced electron injection through the high-kappa HfON/SiO2 DTL, high trapping efficiency of the high-kappa AlN material and effective blocking role of the high-kappa HfAlO BL.