Effects of H₂ plasma and annealing on atomic-layer-deposited Al₂O₃ films and Al/Al₂O₃/Si structures

Abstract

We evaluated the effects of H-2 plasma and thermal treatment on current-voltage (I-V) and capacitance-voltage ( C-V) characteristics using Al/Al2O3/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 Al2O3, 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. (C) 2015 The Japan Society of Applied Physics