Transition-metal-oxide-based resistance-change memories

We provide a status report on the development of perovskite-based transition-metal-oxide resistance-change memories. We focus on bipolar resistance switching observed in Cr-doped SrTiO3 memory cells with dimensions ranging from bulk single crystals to CMOS integrated nanoscale devices. We also discuss electronic and ionic processes during electroforming and resistance switching, as evidenced from electron-parametric resonance (EPR), x-ray absorption spectroscopy, electroluminescence spectroscopy, thermal imaging, and transport experiments. EPR in combination with electroluminescence reveals electron trapping and detrapping processes at the Cr site. Results of x-ray absorption experiments prove that the microscopic origin of the electroforming, that is, the insulator-to-metal transition, is the creation of oxygen vacancies. Cr-doped SrTiO3 memory cells exhibit short programming times (≤100 ns) and low programming currents (<100 µA) with up to 105 write and erase cycles.