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

Abstract

Amorphous Ge-doped HfOx 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 HfOx matrix and the existence of HfSiOx interfacial layer. Capacitance–voltage hysteresis of the Ag-/Ge-doped HfOx/Si/Ag memory capacitor exhibits a memory window of 3.15 V which can maintain for >5 × 104 cycles. Current–voltage characteristics reveal that Poole–Frenkel tunneling is responsible for electron transport in the Ge-doped HfOx film.