Correlation between Oxide Breakdown Field and Effective Oxide Charge Concentration in Ultra-Thin Tunnel Oxide of FG Flash Memory

摘要

Experiments were carried-out to study the relationship between the oxide breakdown field of thin silicon dioxide (SiO2) film, and the effective oxide charges concentration, NEFF. The Metal-Oxide-Semiconductor (MOS) capacitors were used as the test vehicle where standard MOS fabrication process technologies were employed. The main device fabrication processes involved were dry thermal oxidation, photolithography, etching and metallization. After the final sintering process, the electrical device characterization namely the Current-Voltage (I-V) and Capacitance-Voltage (C-V) was carried out on MOS capacitor test structures. The result shows that the oxide's breakdown field is significantly correlated with the amount of the effective oxide charge for the whole studiedthickness range. The breakdown field also exhibited power-law dependency on the oxide thickness. Therefore, it can be qualitatively concluded that the amount of trapped charge in SiO2 would promote the trap-assisted tunneling component and subsequently, causing an oxide breakdown.