MRAM research or technical information

Researchers show how antiferromagnetic STT-MRAM technology can enable higher-density and lower energy memory

Researchers from Northwestern University suggest building STT-MRAM devices from antiferromagnetic materials - as opposed to the currently-used ferromagnetic ones. The researchers say that these materials will enable higher-density devices that feature high speed writing with low currents.

Antiferromagnetic materials are magnetically ordered at the microscopic scale, but not at the macroscopic scale. This means that there is no magnetic force between adjacent bits in MRAM cells built from these materials - which means you can pack them very close together.

Researchers demonstrate that chalcogenide materials can be highly suitable for SOT-MRAM

Researchers from National Taiwan University demonstrate that chalcogenide material BiTe with non-epitaxial structure can give rise to a giant spin Hall ratio and SOT efficiency (~ 200%) without obvious evidence of topologically-protected surface state (TSS).

BiTe material system for SOT-MRAM schema (NUS)

The researchers explain that a clear thickness-dependent increase of the SOT efficiency indicates that the origin of this effect is from the bulk spin-orbit interaction of such materials system. Efficient current-induced switching through SOT is also demonstrated with a low zero-thermal critical switching current density (~ 6×105 A/cm2).

New USMR MRAM structure promises extremly simple design

Researchers from Tokyo's Institute of Technology (Tokyo Tech) developed a new MRAM cell structure (called USMR MRAM) that features a very simple structure with only two layers - which could hopefully enable lower-cost MRAM devices.

USMR MRAM cell structure image

The new design uses a combination of a topological insulator with a ferromagnetic semiconductor which enables a giant unidirectional spin Hall magnetoresistance (USMR).

New super-lattice SL-STT-MRAM enable faster and more efficient memory architecture

Researchers from the National Taiwan University developed a new ultra low power STT-MRAM architecture, called Super Lattice STT-MRAM, or SL-STT-MRAM. The researchers say that SL-STT-MARM simultaneously achieves ultra-high MR ratio, high-speed switching, and low RA.

SL STT MRAM structure

An SL-STT-MRAM is based on an SL-STT-MTJ, which uses a superlattice barrier to replace the single crystalline (MgO) barrier in traditional STT-MTJ. The superlattice barrier is made of alternating metal and insulator layers, in which only amorphous rather than single crystalline is used in the insulator. The SL-STT-MRAM features higher reliability for repeated writing than compared to traditional MgO based STT-MRAM.

Intel researchers demonstrate 2MB STT-MRAM arrays suitable for on-chip L4 cache applications

Intel researchers have demonstrated 2MB STT-MRAM devices that are suitable for on-chip L4 cache applications. Intel says these devices feature data retention, endurance and bit error rates good enough for L4 cache.

Intel slide - STT MRAM L4 Cache

Intel's new STT-MRAM features 20 nm write times, 4 ns read times, an endurance of 1012 cycles and memory retention of one second at 110 degrees. The bit rates are good enough to be handled with error-correcting code (ECC) techniques. To achieve these features, Intel reduced the magnetic junction size to 55 nm (from 70-80 nm it had achieved before).

Researchers in Japan developed a high-speed SOT-MRAM memory cell compatible with 300mm Si CMOS technology

Researchers at Tohoku University demonstrated a high-speed spin-orbit-torque MRAM (SOT-MRAM) memory cell compatible with 300 mm Si CMOS technology.

The SOT device achieved high-speed switching (down to 0.35 ns) and a high thermal stability factor (E/kBT 70) which the researchers say is sufficient for high speed non-volatile memory applications. The device can withstand annealing at 400°C. The researchers used these devices to create a complete SOT-MRAM memory cell.

Researchers demonstrate a new memory device using an OLED and a MOS capacitor

Researchers from TU Dresden developed a novel memory device that is based on a combination of an light emitting material and a metal-oxide semiconductor (MOS) capacitor.

pinMOS memory structure (TU Dresden)

The so-called pinMOS device is a non-volatile memory-capacitor with high repeatability and reproducibility. pinMOS devices can store several states, since charges can be added or removed in controllable amounts. This device can also be controlled (read and write) both electrically and optically. The light emitting material is an OLED device.

Optically-assisted MRAM could outperform current MRAM devices by a factor of 1000

Researchers from the Moscow Institute of Physics and Technology developed a new MRAM architecture that is based on THz pulses which are used to change the spin state. This so-called optically-assisted MRAM is extremely efficient (the power required to switch a "bit" will be a thousand times smaller compared to current MRAM devices) and fast.

The researchers use picosecond-long pulses (3 picoseconds = one light oscillation cycle) on a specially developed structure comprised from micrometer-sized gold antennas deposited on a thulium orthoferrite sample. The researcher admit that the material is excellent for fundamental research, but it may be too early to tell whether it could be used in the future for commercial applications. The researchers tell us that they re trying to raise funds now to start fundamental studies of this new optically-assisted MRAM.