Characteristics of the Fluorinated High- $k$ Inter-Poly Dielectrics

In this letter, the reliabilities and insulating characteristics of the fluorinated aluminum oxide (Al₂O₃) and hafnium oxide (HfO₂) inter-poly dielectric (IPD) are studied for the first time. Compared with the IPDs without fluorine incorporation, the results clearly indicate that fluorine incorporation process is effective to improve the insulating characteristics of both the Al₂O₃ and HfO₂ IPDs, mainly ascribed to the trap density reduction and the smooth interface. Although HfO₂ possesses higher dielectric constant to increase the gate coupling ratio, the results apparently indicate that the fluorine incorporation process is more effective to improve the dielectric characteristics of the Al₂ O₃ IPD than the HfO₂ IPD.