STT-MRAM - Page 18

Spingate is a US-based company focusing on perpendicular MRAM technologies. In November 2009 we have talked to Dr. Alex Shukh, Spingate's co-founder, CTO and CEO, and he explains Spingate's technology . Today Spingate sent us another update.

Spingate says that since 2009 they continued to build their IP portfolio. The company invented and has been developing a new class of nonvolatile spin logic that combines advantages of conventional CMOS logic and MRAM technologies. Spingate's spin logic represents an elegant synthesis of the conventional logic with embedded MRAM cells residing above the silicon. The memory cells have a marginal impact on layout of the logic but provides it with a non-volatility. The spin logic may offer significant performance enhancements of conventional logic devices by eliminating numerous off-chip data flows resulting in speeding up the entire system. The embedded MRAM cells employ spin induced switching mechanism and magnetic materials with either in-plane or perpendicular anisotropy. The spin logic employing perpendicular magnetic materials has better scalability and lower switching current than that based on in-plane materials. The company's logic is especially attractive for application in field programmable gate arrays (FPGAs) due to its non-volatility, simplicity, high speed and reduced chip size. Moreover it can be used for creation of nonvolatile micro-controllers and microprocessors.

NVE reported their financial results, and in the conference call they gave some interesting new details about their MRAM program. Daniel Baker (the CEO) says that NVE 'overcame many of the technical challenges in making MRAM'. In fact, the company is already shipped some sample prototype MRAM chips, but they don't call it 'production' yet. The samples will be for specialized niche applications - but the company sees this as a 'vehicle to develop MRAM technology'. In the future the company hopes to address large volume anti-tamper applications such as to prevent identity theft or improve the security of credit cards and smart cards.

In regards to Everspin being a licensee, here's what they say - "EverSpin is a company that's making and selling commercial MRAM, and they are spin-off of Freescale, which was a spin-off of Motorola. So, we have a long historical relationship. Motorola was an early investor in NVE, and we had research contracts and intellectual property agreements with Motorola. So, we believe that they share our vision for a very bright future for MRAM"

UCLA has been awarded $5.5 million from DARPA to continue develop STT-MRAM technologies. This is the second grant for this project, which brings the total DARPA grants to $10.5 million. The first stage has been completed a year early than planned - by meeting (and in fact significantly surpassing) speed, energy consumption and stability requirements of their STT-RAM (write times smaller than 5 nanoseconds and write energies lower than 0.25 picojoules per bit).

The first phase focused on material and structure innovations. In the second phase, the team will further improve the energy and stability, and will build prototype chips. Another important part of the second phase will be statistical studies needed to facilitate integration with CMOS to realize a product.

During the International Electron Device Meeting (IEDM) exhibition we got some updates about STT-MRAM research done at IBM, Samsung and Hynix-Grandis (who are researching STT-MRAM together).

IBM is working together with TDK and has presented a new 4-kbit perpendicular STT-MRAM array using tunnel junctions. Samsung has presented an on-axis MRAM with a novel MTJ, which they say open he way towards sub-30nm scaling. Using ferromagnetic electrode and a different MTJ structure design, Samsung think that they can scale this to a sub-20nm level.

Grandis has been awarded a new contract from DARPA to use their spintronics and magnetic-material expertise and develop non-volatile spin logic applications: which promises non-volatile, ultra-fast, radiation-hard and radically lower power consumption.

Development work will focus on integrating magnetic tunnel junction (MTJ) materials capable of sensing very small magnetic fields with nano-magnets performing logic operations. The goal is to demonstrate non-volatile spin logic circuits operating at ultra-fast speeds of less than 1 nanosecond and ultra-low power consumption of less than 10 atto-Joules per operation. Such performance coupled with the inherent non-volatility of spin logic devices will enable not just significant reductions in the active power consumption of microprocessors but also the virtual elimination of standby power consumption.

Spin Transfer Technologies (STT) developed the first STT-MRAM device that uses STT's proprietary orthogonal spin transfer technology with a magnetic tunnel junction (MTJ) for memory state read-out. Using the MTJ element makes the device compatible with CMOS logic, and takes the orthogonal spin transfer technology a major step closer to commercialization.

The new device features deterministic switching, resulting in no incubation delays, 100% probability of switching with 500 picosecond pulses utilizing only 250 femtoJoules of energy, 100% magnetoresistance ratio, providing a highly sensitive readout of the magnetic state and bipolar switching behavior (switching upon either polarity of current pulse) potentially allowing simpler or fewer CMOS elements.

Researchers from the University of Minnesota are proposing a new composite structure for STT-RAM devices that reduces current densities by up to a factor of 50. According to the researchers, the major issue with STT-RAM is the high power inputs it requires, and the degradation of the storage elements due to the heat created from these high power inputs. The researchers hope that the new structure will pave the way for STT-RAM to become a universal memory.

The composite structure is formed by inserting one or more soft assisting layers between the recording layer and the layer with a permanent polarity. The soft assisting layers have smaller polarities than the recording layer with each assisting layer closer to the recording layer having a stronger polarity than the previous layer.

Spin Transfer Technologies (STT) and Singulus Technologies will collaborate to apply advanced deposition techniques to support commercial development of STT’s novel MRAM memory devices. The companies will use Singulus TIMARIS deposition tool to create magnetic layer stacks with STT’s design specifications. These layer stacks will then be processed at STT contracted facilities into memory arrays for testing, optimization, and eventually, pre-commercial prototyping.

Singulus has already sold several TIMARIS systems for MRAM companies (including Grandis and Crocus). STT is working towards Orthogonal Spin Transfer MRAM or OST-MRAM for short. Back in October 2008 we have interviewed Vincent Chun, the executive in charge at Spin Transfer Technologies.

Mohamad Krounbi, Hitachi GST's general manager and VP of engineering has left Hitachi to join Grandis. Mohamad will be Grandis Senior VP for engineering.

Grandis has been recently awarded a $8.6 million project for STT-RAM chip development from US's DARPA.

Everspin Technologies has named Phillip LoPresti its president and CEO.

“I am looking forward to building on MRAM’s success across multiple markets and leading Everspin through the next stage of our technology development,” said Phillip LoPresti. “Our strong product portfolio and proven track record positions us to expand market share as more customers recognize the value of our products. Everspin is focused on leveraging its MRAM expertise and resources to accelerate the introduction of new products in development based on our next-generation, high density Spin Torque MRAM technology.”