Impact of Alpha Particles on the Electrical Characteristics of TiO$_{2}$ Memristors

Abstract

Titanium-oxide (TiO 2 ) memristors exposed to 1-MeV alpha particles exhibit only minor changes in the electrical response for ion fluencies up to 10 14 cm 2 . At higher fluence levels, virgin and off-state devices exhibit measurable increases in current conduction between the two platinum (Pt) electrodes. Analysis, supported by radiation transport and numerical device simulations, suggests that radiation-induced displacement damage in the TiO 2 film increases the density of oxygen vacancies, thereby altering both resistivity in the bulk of the transition-metal oxide and the junction characteristics of Pt-TiO 2 interface. Nevertheless, the experimental results indicate continued switching functionality of the memristors even after exposure to 10 15 cm 2 alpha particles. The high intrinsic vacancy density in the devices prior to radiation exposure is identified as the primary feature contributing to apparent radiation hardness.

Reconfigurable Memristive Device Technologies

“…[216]. While at present the susceptibility of cation-based memory elements to displacement damage is not known, Barnaby et al [220] reported displacement damage effects in anion-based memristors, engineered with TiO 2 as the transition metal oxide. TiO 2 memristors, like most anionbased technologies, operate by controlling the distribution of oxygen vacancies in the TMO film.…”

“…By contrast, the threats to anion-based RRAM posed by ionizing radiation were demonstrated to be minimal in [223] and [228]. In 2011, Barnaby et al reported that radiation-induced displacement damage was indeed the primary cause of memory loss in the TiO 2 memristors [220]. The devices reported on in [220] were fabricated by HP labs and exposed to 1-MeV alpha particles.…”

“…In 2011, Barnaby et al reported that radiation-induced displacement damage was indeed the primary cause of memory loss in the TiO 2 memristors [220]. The devices reported on in [220] were fabricated by HP labs and exposed to 1-MeV alpha particles. The radiation experiments showed that the memristors did exhibit memory loss; specifically, a radiation-induced switch from the high-resistance (off-) state to the low-resistance (on) state.…”

“…This alters the resistivity of the TMO bulk and enhances carrier tunneling in the device. Through the combined use of radiation transport and numerical device simulations, it was shown in [220] that increased current conduction could be modeled by relating an increase the effective doping concentration in the TiO 2 film to the increased number of vacancies created from atomic displacements. Fig.…”

Sensitivity of metal oxide memristors to radiation-induced displacement damage

“…In work from Tong, et al TiO 2 devices were irradiated with 941-MeV Bi ions. Later work used 350-keV protons, neutrons [6] and 1-MeV alpha particles [2]. At Sandia, TaO x -based devices have been exposed to a variety of proton energies, including 4.5-MeV and 105-MeV, and to 800-keV silicon ions [3].…”