Cross-Point Arrays with Low-Power ITO-HfO2 Resistive Memory Cells Integrated on Vertical III-V Nanowires

Vertical nanowires with cointegrated metal-oxide-semiconductor field-effect-transistor (MOSFET) selectors and nonvolatile resistive random access memory (RRAM) cells represent a promising candidate for fast, energy-efficient, cross-point memory cells. This paper explores indium-tin-oxide-hafnium-dioxide RRAM cells integrated onto arrays of indium-arsenide (InAs) vertical nanowires with a resulting area of 0.06 µm² per cell. For low current operation, an improved switching uniformity over the intrinsic self-compliant behavior is demonstrated when using an external InAs nanowire MOSFET selector in series. The memory cells show consistent switching voltages below ±1 V and a switching cycle endurance of 10⁶ is demonstrated. The developed fabrication scheme is fully compatible with low-ON-resistance vertical III-V nanowire MOSFET selectors, where operational compatibility with the initial high-field filament forming is established. Due to the small footprint of a vertical implementation, high density integration is achievable, and with a measured programming energy for 50 ns pulses at 0.49 pJ, the technology promises fast and ultralow power cross-point memory arrays.