Low-power resistive random access memory by confining the formation of conducting filaments

Abstract

Owing to their small physical size and low power consumption, resistive random access memory (RRAM) devices are potential for future memory and logic applications in microelectronics. In this study, a new resistive switching material structure, TiOx/silver nanoparticles/TiOx/AlTiOx, fabricated between the fluorine-doped tin oxide bottom electrode and the indium tin oxide top electrode is demonstrated. The device exhibits excellent memory performances, such as low operation voltage (<±1 V), low operation power, small variation in resistance, reliable data retention, and a large memory window. The current-voltage measurement shows that the conducting mechanism in the device at the high resistance state is via electron hopping between oxygen vacancies in the resistive switching material. When the device is switched to the low resistance state, conducting filaments are formed in the resistive switching material as a result of accumulation of oxygen vacancies. The bottom AlTiOx layer in the device structure limits the formation of conducting filaments; therefore, the current and power consumption of device operation are significantly reduced.

Resistive Random Access Memory (RRAM): an Overview of Materials, Switching Mechanism, Performance, Multilevel Cell (mlc) Storage, Modeling, and Applications

“…The resistance switching phenomenon has been observed in a variety of oxides, but binary metal oxides have been extensively studied as a preferred switching material for future non-volatile memory applications primarily due to their compatibility with the CMOS BEOL processing. Various metal-oxide-based materials exhibiting the non-volatile resistance switching such as hafnium oxide (HfO x ) [18][19][20][21][22][23], titanium oxide (TiO x ) [24][25][26][27][28][29][30][31], tantalum oxide (TaO x ) [32][33][34][35][36], nickel oxide (NiO) [37][38][39][40], zinc oxide (ZnO) [41][42][43][44][45][46], zinc titanate (Zn 2 TiO 4 ) [47], manganese oxide (MnO x ) [48,49], magnesium oxide (MgO) [50], aluminum oxide (AlO x ) [51][52][53], and zirconium dioxide (ZrO 2 ) [54][55][56][57][58] have drawn the most attention and have been studied extensively during the past several years. These metal oxides are deposited usually by pulse laser deposition (PLD), atomic layer deposition (ALD), and reactive sput- tering.…”

Graphene/h-BN Heterostructures for Vertical Architecture of RRAM Design

“…It is worth noting that graphene plane electrode becomes p-doped by the H 2 O dopant introduced during the wet transfer process 49 , indicating that the work function of graphene is changed from the charge-neutral point 4.6 eV to 5 eV. In this study, TiO x deposited by ALD is usually oxygen deficient 25 , 26 , so that the conducting filaments have formed in the TiO x layer. The AlO x layer has a better insulating property; nonetheless, it is so thin that the electroforming step is not required.…”

“…To further elaborate the aforementioned conduction mechanisms involved, the corresponding carrier transport mechanisms and the formation of conducting filaments based on the push-pull mechanism are presented in a diagrammatic manner in order to explain the resistive switching characteristics 25 , 26 , as shown in Fig. 6 .…”

“…Thus various emerging memories with new storage mechanisms have been put forward as candidates for flash memory replacement, such as ferroelectric random access memory (FRAM) 6 – 8 , magnetoresistive RAM (MRAM) 9 – 11 and phase-change RAM (PRAM) 12 – 15 , etc. Among them, the resistive random access memory (RRAM) is the most promising candidate to overcome the technological limitations for the next-generation non-volatile memory, because of its advantages, such as high-speed operation, low power consumption, high endurance, and long retention time 16 – 26 . The simple fabrication process, good scaling capability and low bit cost 27 – 29 are some of the potential merits presented in some recent studies to demonstrate that several 3D vertical RRAM are competitive with the high bit density of 3D NAND flash memory.…”

High-Performance InGaZnO-Based ReRAMs

“…Various treatments of IGZO layers have also been made to improve the performance of ReRAMs, e.g., using ultraviolet (UV) irradiation [26], microwave irradiation [34] and element doping [35]. Moreover, the effects of electrode materials on device characteristics have been studied [36], [37]. Inert metals like platinum (Pt) have been used as the ReRAM electrode, especially as the bottom electrode [5], [17], [18], [37].…”