Fabrication and electronic characterization of epitaxial Gd2O3-doped HfO2 dielectrics on Si

The 5-nm-thick HfO₂ film doped with 35 mol% Gd₂O₃ (GDH) as a high k dielectric has been epitaxially grown on Si (100) substrate by pulsed laser deposition (PLD). In situ reflection high-energy electron diffraction (RHEED) evolution of the (100)-oriented GDH during the deposition has been investigated and shows that a two-dimensional (2D) single crystalline GDH grows with a smooth surface. The in-plane orientation relationship between (100) Si substrate and (100) GDH film adopts a cube on cube mode, which is (100)_GDH//(100)_Si and [110]_GDH//[110]_Si. The capacitance-voltage (C-V) curve shows an overall dielectric constant value of 21, capacitance equivalent thickness (CET) of 0.9 nm, and a negligible flatband shift.