Permanent Data Storage in ZnO Thin Films by Filamentary Resistive Switching

Abstract

Resistive memories are considered the most promising candidates for the next generation of non-volatile memory; however, attention has so far been limited to rewritable memory features for applications in resistive random access memories (RRAM). In this article, we provide a new insight into the applicability of resistive memories. The characteristics of non-rewritable resistive memories (NRRM) were investigated. Devices with Pt/ZnO/ITO architecture were prepared using magnetron sputtering, upon which various bipolar and unipolar resistive switching tests were performed. The results showed excellent distinction between the high resistance state (HRS) and low resistance state (LRS), with RHRS/RLRS = 5.2 × 1011 for the Pt/ZnO/ITO device with deposition time of 1 h. All samples were stable for more than 104 s, indicating that the devices have excellent applicability in NRRMs.

Memristor Behavior under Dark and Violet Illumination in Thin Films of ZnO/ZnO-Al Multilayers

“…This type of behavior is widely known in the scientific literature as the fingerprint of a memristor, where a device constructed in the form of metal-insulator (semiconductor)-metal presents electrical resistance dependent on the history of excitation by the application of an external electric field [1,7,26,35]. The gradual conductivity increasing with the application of voltage is a desirable aspect related to memristors, as the memory effect associated to these devices is based on a change in the resistance state, usually a higher resistive state R OFF and lower resistive states, reaching a minimum resistance level at R ON [5,8,36]. Computational logic states are, therefore, associated with these two values of electrical resistance (bit 0-R OFF ; bit 1-R ON ).…”

“…Computational logic states are, therefore, associated with these two values of electrical resistance (bit 0-R OFF ; bit 1-R ON ). However, in this type of application, the memristors commonly present filamentary resistive switching mechanisms, where a conductive filament is formed by connecting one electrode to another [5,6,37]. The samples analyzed in this chapter are mechanisms based on a homogeneous resistive switching, in which electrical resistance states are gradually modified and controlled [26,36,38].…”

“…In 2008, in Hewlett-Packard (HP) laboratories, thin films of titanium dioxide prepared with two terminals presented memristor characteristics [4]. Their basic structure was based on epitaxial growth of metal-insulator-metal (MIM) thin films [5][6][7]. With the experimental development of memristors in HP laboratories, there has been increasing research in this area, and several materials have been constructed in the MIM structure for analysis of memristive behavior.…”

“…In addition, new transparent devices are being developed in applications of neuromorphic circuits [4,7,15] and adaptive systems [16,17] in which they are based on resistive commutation depending on the history of the electric voltage application. Among the various materials that have memristor characteristics, ZnO stands out for its low toxicity, low cost, wide resistive switching ratio ( R off / R on ~10 11 ), low power consumption, fast recording, and highdensity storage [5,10,18,19]. For the construction of a transparent MIM system, an indium tin oxide (ITO) substrate can be used because of its optical properties (transmittance ~90%) and electrical properties (sheet resistance ~20 Ω / sq ) [20].…”

A Review of Microwave Synthesis of Zinc Oxide Nanomaterials: Reactants, Process Parameters and Morphologies

“…Once doped, they display new properties, e.g., electrical conductivity, magnetic, magneto-optical, photocatalytic, antibacterial and optical [ 74 , 161 , 220 , 221 , 222 , 223 , 224 , 225 , 226 , 227 , 228 , 229 , 230 , 231 , 232 ]. At present, various ZnO nanostructures are being used in attempts to produce a new generation of light-emitting diodes [ 233 , 234 ], lasers [ 235 ], field emission devices [ 236 , 237 ], memory carriers [ 238 , 239 ], solar cells [ 240 , 241 , 242 , 243 , 244 , 245 , 246 ], liquid crystals [ 247 ], polymer nanocomposites [ 248 , 249 , 250 , 251 ], food packaging materials [ 252 , 253 , 254 , 255 , 256 , 257 , 258 ], transparent ultraviolet light absorbers in unplasticised polymers [ 259 ], catalysts [ 260 ], photoluminescent NPs [ 261 ], photocatalysts ...…”