Effects of H_2 plasma and annealing on atomic-layer-deposited Al_2O_3 films and Al/Al_2O_3/Si structures

摘要

We evaluated the effects of H_2 plasma and thermal treatment on current-voltage (Ⅰ-Ⅴ) and capacitance-voltage (C-V) characteristics using Al/ Al_2O_3/Si. H_2 plasma treatment reduced the concentration of C and enhanced the diffusion of Si and O atoms and the mean breakdown field strength. The breakdown field increased significantly after rapid thermal annealing (RTA) due to crystallization and the formation of an interface layer between Si and Al_2O_3, which was confirmed by TEM, secondary ion mass spectroscopy (SIMS), and three-dimensional (3D) atom probe tomography. H_2 plasma treatment produced a negative fixed charge due to the outgassing of C and H_2, and RTA produced a positive fixed charge.