Leakage current conduction behaviors of 0.65 nm equivalent-oxide-thickness HfZrLaO gate dielectrics

The high κ gate dielectrics of MOS capacitors with LaO/HfZrO stacked (denoted as HfZrLaO) have been fabricated by atomic-layer-deposited (ALD). In this study, the data show that the gate leakage current density (J_g) is about 1.9 A/cm², and the equivalent oxide thickness (EOT) is about 0.65 nm with quantum effects taken into account. The analysis of the leakage current conduction characteristics is based on the temperature dependence of the leakage current from 300 to 475 K. The dominant current conduction behaviors are Schottky emission in the region of low electric fields (<1 MV/cm) and high temperatures (450-475 K), Poole-Frankel (P-F) emission in the region of medium electric fields (2.3-3.83 MV/cm) and low temperatures (300-350 K), and Fowler-Nordheim (F-N) tunneling in the region of high electric fields (>4 MV/cm) and low temperatures (<300 K). The electron barrier height (Φ_B) at gate interface and the trap energy level (Φ_t) in the dielectric are extracted to be 1.07 and 1.38 eV, respectively.