NanoCell Electronic Memories (original) (raw)
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Ketabe sabz , 2022
(Nano molecular memory) By using the structure of nanomolecular memory, the size of memory bits can be substantially reduced, thereby increasing the density and efficiency of magnetic memory and lowering its cost and cost. Nano-lithographic methods are now being used to provide some very powerful memories. Nanoelectronics Science and Technology offer different nano-molecular memory capabilities. Photofraction materials, for example, represent only one type of optical memory. In fact, with the use of nanotechnology, the storage capacity of information can be increased by a thousand times or more. Data storage is a very important and necessary topic that can be done in various ways through nanomolecular memory. One of the new data storage tools is the use of nickel quantum dots in nanometer sizes that are expected to Use terabytes of data storage. Due to nano molecular memory, there is a high potential for activity in this field
Recent advances in nanoparticle memories
Materials Science and Engineering: B, 2005
Nanoparticle memories have made their point during last years as a possible solution to overcome the scaling issue of electronic non-volatile memories. Ultimately, we are looking for nanoparticle memories to significantly decrease the voltage needed to write/erase the memory without compromising its retention characteristics. Several approaches have been reported for semiconductor nanoparticle formation using techniques such as chemical vapor deposition, molecular beam epitaxy or sputtering. In the present review emphasis is placed on a silicon nanoparticle memory resulting from low-energy ion implantation of silicon within a thin oxide layer and subsequent annealing. This process allows for the formation of a two-dimensional array of silicon nanoparticles within the gate oxide in one processing step making the process attractive for CMOS integration. Material issues related with ion implantation energy, dose and annealing ambient for optimum device performance are addressed. As an alternative to semiconductor nanoparticles, metallic nanoparticles have been investigated since they have the potential for more versatile engineering of energy barriers that would allow improved data retention for memory devices operating at low voltages. Processing approaches for metallic nanoparticle formation are addressed and corresponding memory device performance is discussed for the particular case of room temperature deposited metallic nanoparticles by chemical methods.
Planar non-volatile memory based on metal nanoparticles
Materials Research Society Symposium Proceedings, 2011
Resistive switching properties of silver nanoparticles hosted in an insulating polymer matrix (poly(N-vinyl-2-pyrrolidone) are reported. Planar devices structures using interdigitated gold electrodes were fabricated. These devices have on/off resistance ratio as high as 10 3 , retention times reaching to months and good endurance cycles. Temperature-dependent measurements show that the charge transport is weakly thermal activated (73 meV) for both states suggesting that nanoparticles will not aggregate into a metallic filament.
Study of the room temperature molecular memory observed from a nanowell device
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2005
We tested the electrical characteristics of an oligo͑phenylene ethynylene͒ ͑OPE͒ molecule with one nitro side group, an OPE with two nitro side groups, and an OPE with no nitro side groups in our nanowell device. The OPE molecule with nitro side group͑s͒ showed switching behavior with memory as well as nonreversible negative differential resistance ͑NDR͒. Current-voltage ͑I-V͒ characteristics showed a high conductivity state that switched to a low conductivity state upon the application of a threshold voltage. This low state held until the opposite threshold voltage was applied and the device switched back to the high conductivity state. The OPE with no nitro side groups did not show memory or NDR. In this work, we report the complete switching behavior observed including the device yield, average threshold voltage, and the average high to low current ratios.
Discontinuous gold films for nanocell memories
An important component to the nanocell, among other self-assembled networks, is the fabrication of a framework by which molecular elements can be interconnected. This framework must be nanometric in scale, created in a material suitable for attachment chemistries and remain electrically discontinuous until molecular attachment. Utilizing the Volmer-Weber mechanism by which gold grows on silicon dioxide surfaces, nanometric islands of gold are fabricated to provide this framework. Using standard photolithography techniques, the regions where these islands are located are well defined. A two-layer photoresist stack is developed that prevents edge shorting around the boundaries of each region. The discontinuous gold films fabricated in this study are repeatable, offer a fill factor of 63%, and are easily patterned down to the onemicron scale.
Nanoparticle-based memories : concept and operation principles
In this paper, we review the fabrication and the electrical characteristics of metal-insulator-semiconductor (MIS) devices with semiconductor quantum dots (QD) embedded into the gate dielectric. Our results originate from experiments performed the last decade and cover Si QDs realized by low-energy ion-beam synthesis (IBS) as well as GaN QDs formed by molecular beam deposition (MBD). Besides the basic capacitance-to-voltage (C-V) and current-to-voltage (I-V) characterization, the memory properties of the fabricated MIS devices were investigated in terms of memory window under pulse operation and charge retention. The optimization of Si-QD memory cells is reviewed and a methodology for both the extraction of various device parameters and the identification of mechanisms governing the charge loss process are presented. GaN QDs, which exhibit negative conduction band-offset with respect to the Si conduction band, offer an interesting alternative to Si QDs as discussed herein based on our investigations of GaN-QD capacitors fabricated by a complementary-metal-oxide-semiconductor (CMOS) compatible process.
Logic and memory with nanocell circuits
IEEE Transactions on Electron Devices, 2003
Molecular electronics is an emerging field that seeks to build faster, cheaper, denser computers from nanoscale devices. The nanocell is a molecular electronics design wherein a random, self-assembled array of molecules and metallic nanoparticles is addressed by a relatively small number of input/output pins. The challenge then is to program the nanocell post-fabrication. We have previously demonstrated the ability to program individual simulated nanocells as logic gates. In this paper, we further explore the problem of programming nanocells and consider connecting nanocells into circuits using bistable latches at the interconnects. These latches are critical because they permit signal restoration. Simulated nanocell circuits for logic and memory are presented here.
Metal nanocrystal memories-part II: electrical characteristics
IEEE Transactions on Electron Devices, 2002
This paper describes the electrical characteristics of the metal nanocrystal memory devices continued from the previous paper [1]. Devices with Au, Ag, and Pt nanocrystals working in the F-N tunneling regime have been investigated and compared with Si nanocrystal memory devices. With hot-carrier injection such as the programming mechanism, retention time up to 10 6 s has been observed and 2-bit-per-cell storage capability has been demonstrated and analyzed. The concern of the possible metal contamination is also addressed by current-voltage (-) and capacitance-voltage (-) characterizations. The extracted inversion layer mobility and minority carrier lifetime suggest that the substrate is free from metal contamination with continuous operations.
Electrical Manipulation of Nanofilaments in Transition-Metal Oxides for Resistance-Based Memory
Nano Letters, 2009
The fabrication of controlled nanostructures such as quantum dots, nanotubes, nanowires, and nanopillars has progressed rapidly over the past 10 years. However, both bottom-up and top-down methods to integrate the nanostructures are met with several challenges. For practical applications with the high level of the integration, an approach that can fabricate the required structures locally is desirable. In addition, the electrical signal to construct and control the nanostructures can provide significant advantages toward the stability and ordering. Through experiments on the negative resistance switching phenomenon in Pt-NiO-Pt structures, we have fabricated nanofilament channels that can be electrically connected or disconnected. Various analyses indicate that the nanofilaments are made of nickel and are formed at the grain boundaries. The scaling behaviors of the nickel nanofilaments were closely examined, with respect to the switching time, power, and resistance. In particular, the 100 nm × 100 nm cell was switchable on the nanosecond scale, making them ideal for the basis for high-speed, high-density, nonvolatile memory applications.