A Self-Rectifying Unipolar HfOx Based RRAM Using Doped Germanium Bottom Electrode

A self-rectifying unipolar RRAM based on HfOx dielectrics using highly doped n-type germanium substrate as the bottom electrode is proposed for the first time. The RRAM cells exhibit a stable unipolar resistive switching behavior. Owning to Schottky barrier between defect states in HfOx layer and n-Ge substrate, RRAM cells possess a self-rectifying behavior in LRS which eliminates the read-out errors induced by leakage current paths in cross-bar array structure. The demonstrated RRAM device shows high ON/OFF ratio (>5 x 10(2) @ 0.5 V), and its effective Schottky barrier height is also addressed. The demonstrated HfOx-based RRAM devices provide a promising candidate as non-volatile memory devices using Ge-based technology. (C) 2013 The Electrochemical Society. All rights reserved.