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Display Omitted The retention behavior of HfO2-based memories is analyzed as a function of Al doping.The high resistance state reveals two main mechanisms of data retention degradation.Gradual resistance lowering increases with Al doping due to enhanced diffusion.High Al concentrations induce an increase of sharp resistance losses.Tailoring the Al concentration allows to limit an excessive retention degradation. The retention behavior of HfO2-based resistive switching memory cells (RRAM) is characterized as a function of Al doping concentration, which was previously reported to be a viable method for the improvement of the switching uniformity. While the low resistance state (LRS) does not exhibit any major variation up to 106s for all the tested devices, two retention loss mechanisms can be identified for the high resistance state (HRS). The main HRS trend follows a temperature-activated gradual decrease of the resistance, which also depends on the doping concentration. In addition, tail bits of the population distribution show a very fast retention loss process that strongly depends on the doping concentration.

Resistance switching random access non-volatile memories (ReRAM) could represent the leading alternative to floating gate technology for post 32 nm technology nodes. Among the currently investigated materials for ReRAM, transition metal binary oxides, such as NiO, CuxO, ZrOx, TiO2, MgO, and Nb2O5 are receiving increasing interest as they offer high potential scalability, low-energy switching, thermal stability, and easy integration in CMOS fabrication. In this work we investigate the resistive switching properties of NiO and Nb2O5 films grown by electron beam and atomic layer deposition (ALD) as a function of growth technique and electrode materials. The polycrystalline NiO and amorphous Nb2O5 films are initially in the high resistance state and exhibit reproducible unipolar switching after an appropriate forming stage. Beside noble metal electrodes, particular focus is on n(+)-Si, W, and TiN materials which are compatible with CMOS device fabrication process. (C) 2008 Elsevier B.V. All rights reserved.