Defect Analysis and Reliability Characteristics of (HfZrO₄)_1-(SiO₂)x High- Dielectrics

Hafnium zirconium silicon oxide ((HfZrO₄)1-x(SiO₂)x) materials were investigated through the defect analysis and reliability characterization for next generation high-κ dielectric. Silicate doped hafnium zirconium oxide (HfZrO4) films showed a reduction of negative flat-band voltage (V_fb) shift compared to pure HfZrO₄. This result was caused by a decrease in donor-like interface traps (Dit) and positive border traps (N_bt). As the silicon oxide (SiO₂) content increased, the V_fb was shifted in the positive direction from -1.23 to -1.10 to -0.91 V and the slope of the capacitance-voltage (C-V) curve increased. The nonparallel shift of the C-V characteristics was affected by the D_it, while the N_bt was responsible for the parallel C-V curve shift. The values of D_it reduced from 4.3 × 10¹¹, 3.5 × 10¹¹, and 3.0 × 10¹¹ cm^-2eV^-1, as well as the values of N_bt were decreased from 5.24, 3.90 to 2.26 × 10¹² cm^-2. Finally, reduction of defects in the HfZrO₄-base film with an addition of SiO₂ affected the gate oxide reliability characteristics, such as gate leakage current (J_G), bias temperature stress instability (BTSI), and time dependent gate dielectric breakdown (TDDB).