Charge storage characteristics and tunneling mechanism of amorphous Ge-doped HfO_x films

Amorphous Ge-doped HfO_x films have been deposited on p-Si(100) substrates by means of RF magnetron sputtering. Microstructural investigations reveal the partial oxidation of doped Ge atoms in the amorphous HfO_x matrix and the existence of HfSiO_x interfacial layer. Capacitance-voltage hysteresis of the Ag-/Ge-doped HfO_x/Si/Ag memory capacitor exhibits a memory window of 3.15 V which can maintain for >5 x 10⁴ cycles. Current-voltage characteristics reveal that Poole-Frenkel tunneling is responsible for electron transport in the Ge-doped HfO_x film. (orig.)