March 2012

A*STAR scientists have filed a patent on low-density parity-check (LDPC) coding with soft decision decoding. This is an advanced error correction coding scheme STT-MRAM devices. Hopefully this new scheme will enable more relaxed smaler STT-MRAM designs that can rely on the error-correction.

STT-MRAM devices suffer from cell errors due to imperfections in the fabrication process (variation in the tunneling oxide thickness and cross-section area). The researchers explain that conventional (hard decision) error correction codes do not work very well on STT-MRAM cells. The new soft decision decoding works on the probability of each detected bit as being a 0 or 1 (i.e. soft reliability), and hence has less decoding errors than the conventional hard decision decoding.

Singulus Technologies announced it has recieved two new orders for TIMARIS vacuum deposition systems. TIMARIS systems can be used for MRAM development or research, it's not clear what will those new systems be used for. Singulus did say that they already received orders for four TIMARIS systems in 2012 in different configurations. The total order value for 2012 is apparently over €13 million.

Researchers at the Max Planck Institute of Microstructure Physics in Halle developed a new switching mechanism for magnetic current. The new mechanism could be used to store information in four states of a storage point, not just two - which doubles storage density or lowers the size of MRAM devices. It may also have other implications for Spintronic Devices. The idea is to use a short electric pulse to change the magnetic transport properties of a material sandwich consisting of a ferroelectric layer between two ferromagnetic materials.

In ferroelectric materials, voltage switches between the two directions of an electric polarisation depending on its polarity not unlike when a magnetic field permanently reverses the polarity of a ferromagnet. As ions shift within the material structure during this process, the polarisation remains intact, even after the voltage has been reduced. It is possible, however, to reverse the switch again with a similarly large voltage with reversed polarity.