Nanoporous Silicon Oxide Memory

Abstract

Oxide-based two-terminal resistive random access memory (RRAM) is considered one of the most promising candidates for next-generation nonvolatile memory. We introduce here a new RRAM memory structure employing a nanoporous (NP) silicon oxide (SiOx) material which enables unipolar switching through its internal vertical nanogap. Through the control of the stochastic filament formation at low voltage, the NP SiOx memory exhibited an extremely low electroforming voltage (∼ 1.6 V) and outstanding performance metrics. These include multibit storage ability (up to 9-bits), a high ON-OFF ratio (up to 10(7) A), a long high-temperature lifetime (≥ 10(4) s at 100 °C), excellent cycling endurance (≥ 10(5)), sub-50 ns switching speeds, and low power consumption (∼ 6 × 10(-5) W/bit). Also provided is the room temperature processability for versatile fabrication without any compliance current being needed during electroforming or switching operations. Taken together, these metrics in NP SiOx RRAM provide a route toward easily accessed nonvolatile memory applications.

Semiconductor-Free Nonvolatile Resistive Switching Memory Devices Based on Metal Nanogaps Fabricated on Flexible Substrates via Adhesion Lithography

“…In general a high bias is applied to the system with a compliance current set to prevent complete breakdown [56]. For nanogap electrodes on SiO2, the forming voltage has been found to be 12 V for a 15 nm gap [28], 29 V for a 50 nm gap [33] and 1.6 V for 2 nm gaps [57]. These values would indicate a dielectric strength of SiO2 in the range 6-8 MV cm -1 , a value on par with those reported in the literature [58].…”

“…The only difference in the reported mechanisms is that for nanogap dimension change due to material migration switching, a sweep about the set voltage (e.g. +10 V → -1 V, [54] or +9 V → + 3 V [53] ) is employed, whereas for oxide switching, a pulse at the set voltage suffices [28], [31], [33], [55], [57].…”

Surface engineering to achieve organic ternary memory with a high device yield and improved performance

“…After decades of intensive research, many inorganic oxides, 7 polymers 8 and small molecules 9,10 have been found to exhibit multilevel resistive switching behaviours and are thus considered candidate active materials for multilevel RRAMs. However, to enable industrial use, RRAM devices must show good reproducibility, including a high multilevel memory device yield and narrow distribution of OFF/ON1/ON2 switching voltages.…”

An All-Memristor Deep Spiking Neural Computing System: A Step Toward Realizing the Low-Power Stochastic Brain

“…Unlike some types of memristors, the a − Si memristors require high write voltages. For an example, the nanoporous SiO x based devices have very low forming voltages (∼ 1.4V) [35]. Having smaller operating voltages in memristive crossbars require sophisticated sensing mechanisms.…”