Effects of NH3 annealing on interface and electrical properties of Gd-doped HfO2/Si stack

Effects of NH3 rapid thermal annealing (RTA) on the interface and electrical properties of Gd-doped HfO2 (GDH)/Si stack were investigated. The process of NH3 annealing could significantly affect the crystallization, stoichiometric properties of GDH film and the interface characteristic of GDH/Si system. NH3 annealing also led to the decrease of interface layer thickness. The leakage current density of Pt/GDH/p-Si MOS capacitor without RTA was 2×10−3 A/cm2. After NH3 annealing, the leakage current density was about one order of magnitude lower (3.9×10−4 A/cm2). The effective permittivity extracted from the C-V curves was ∼14.1 and ∼13.1 for samples without and with RTA, respectively.