Applications of Ion Beam Irradiation in Multifunctional Oxide Thin Films: A Review

Abstract

Multifunctional oxide thin films exhibit a broad palette of properties, such as ferroelectricity, piezoelectricity, dielectricity, superconductivity, and metal-insulator transition (MIT); therefore, they have long been a research focus in both condensed matter physics and materials science communities. Recently, ion beam irradiation emerges as an effective approach to modify the properties of oxide thin films by introducing defects, strains, structural transitions, etc., and many interesting works have been published. A timely review of those works is therefore urgently needed. Here, we present a comprehensive review of the applications of ion beam irradiation in tailoring oxide thin film functionalities, including ferroelectric properties, dielectric and piezoelectric properties, multilevel MIT process, gas sensitivity, memristive behavior, and magnetic characters, which may be useful for developing capacitors, sensors, memories, and optical devices with enhanced performances. Finally, we discuss the challenges and future perspectives for the usage of ion beam irradiation for tuning the performance of oxide materials and devices.

Radiation Response of HfOx-Based Resistive Random Access Memory (RRAM) Devices

“…PL spectroscopy was used to analyze the vacancy defects in these films. These oxygen vacancies are very critical for the filament formation processes that govern the RS phenomenon. − The PL data of the pristine sample shown in Figure (a) indicates the presence of oxygen vacancies in the pristine films. Similarly, the PL spectra and the de-convoluted peaks for the SHI-irradiated samples, with different fluence values, are as shown in Figure (a–e).…”

“…SHI irradiation with 120 MeV (Ag ion) was employed to elucidate the effects of ion irradiation on the switching parameters of these RRAM devices. As an energetic ion interacts with a material, it loses its energy via electronic energy loss ( S e , which dominates for higher energies >0.5 MeV/u) and nuclear energy loss ( S n , which dominates for lower energies <0.5 MeV/u) processes. ,,− The critical value of S e for forming ion tracks (or damaged regions) in HfO 2 was estimated to be about 20 keV/nm. ,, A notable point is that the Ag ions will not get implanted in the film. Therefore, Ag ions will come to rest only in the substrate.…”

“…There are several reports on the investigation of total dose effects in HfO 2 - and HfO x -based RRAM devices. ,,,− However, the understanding of the effects of ion irradiation, particularly swift heavy ion (SHI) irradiation, on the performance of these devices is still to be developed. ,− Recent reports on the influence of high-energy heavy-ion (1.1 GeV Au) irradiation on the performance of monoclinic-HfO x -based RRAMs (TiN/m-HfO 2‑ x /Pt/Au/c-Al 2 O 2 ) emphasize the significance of such studies in this area. , Further, we have recently shown the effects of SHI irradiation on reducing the set and reset voltages and the spread in their distribution as a function on fluence of amorphous RF-sputtered HfO 2 -based RRAM devices. In this paper, the effects of SHI irradiation on the performance of non-stoichiometric electron beam evaporation HfO x film-based RRAM devices are presented.…”

State-of-the-Art Research on Chemiresistive Gas Sensors in Korea: Emphasis on the Achievements of the Research Labs of Professors Hyoun Woo Kim and Sang Sub Kim

“…The properties mainly change according to the characteristics and quantity of the incident atoms, their diffusion characteristics, and the number and types of defects. At high energies, electron excitation/ionization occurs (electronic energy loss) due to inelastic collisions [ 131 , 132 , 133 ]. Kwon et al [ 134 ] irradiated SnO 2 NWs with He ions (45 MeV) through different ionic fluences, where the NO 2 response of the sensor increased considerably with an increase in the ion fluence.…”

Symmetric Trilayer Dielectric Composites with High Energy Density Using a Low Loading of KNbO3 Nanosheets

“…Recently, dielectric nanocomposites that combine the advantages of high relative permittivity from a ceramic phase with high breakdown strength from a polymer matrix have presented a promising strategy to obtain high energy density. − Many efforts have been dedicated by incorporating various ceramics nanofillers (e.g., Na 0.5 Bi 0.5 TiO 3 , − BaTiO 3 , ,, NaNbO 3 , , TiO 2 , − etc.) into polymer matrixes (e.g., poly­(vinylidene fluoride) (PVDF), ,,− polyetherimide (PEI), − and poly­(methyl methacrylate) (PMMA) ,− ) to optimize the dielectric properties and electric breakdown strength.…”