Samsung is going to walk the spin-transfer torque by buying Grandis, and will use its capabilities to develop next-generation memory.
Spin-transfer torque RAM (STT-RAM) is characterised as having "a spin-polarised current in a tunnel magneto resistance element. Normally an electric current is not polarised as half its electrons are classed as spin-up and half as spin-down. This can be changed by passing a current through a thick magnetic layer such that it has more spin-up electrons than spin-down or vice-versa."
The idea is to transfer the spin-polarised current's spin characteristic to a magnetic element, with the direction of magnetism signifying a binary one or zero.
A Toshiba statement says: "Data in MRAM can be determined by measuring the difference in resistance from magnetisation on a magnetic tunnel junction (MTJ). Data is written and saved by reorienting the magnetisation of a thin magnetic layer in a tunnel magneto-resistance (TMR) element using a spin-polarised current."
The technology is also known as MRAM (magneto-resistive RAM), and promises very fast access memory, with DRAM speed plus the non-volatility of NAND. In this it is similar to Phase Change Memory (PCM), another promising post-NAND technology.
Grandis, based in Silicon Valley, has become well-known in the STT-RAM field, and Hynix licensed its IP in April, 2008. Renasas is also thought to have licensed Grandis IP for its STT-RAM development. Now Samsung, the world's largest memory supplier, has bought it.
A rare gem
Coincidentally Hynix and Toshiba have just signed a joint MRAM development agreement. They intend to develop the technology and then manufacture MRAM product in a joint-venture. The two think mobile internet devices could use the stuff to hold stacks of data, access it at blinding speed, and enjoy long battery life.
Oh Chul Kwon, Hynix's CEO, said: "MRAM is a rare gem full of exciting properties, like ultra high-speed, low power consumption, and high capacity, and it will play the role of key factor in driving advances in memories. It will also be a perfect fit for growing consumer demand in more sophisticated smartphones. MRAM is our next growth platform."
A Toshiba spokesperson, Kiyoshi Kobayashi, president and CEO of Toshiba's Semiconductor and Storage Products Company, added: "We will strongly promote initiatives in integration of storage solutions including MRAM, NAND, and HDD." So he sees MRAM, flash and hard disk drives working together in some tiered way...
$30m-$60m price tag
Grandis was founded in 2002 and is headquartered in Milpitas, California. Investors include Applied Ventures, Sevin Rosen Funds, Matrix Partners, Incubic and Concept Ventures as well as DARPA, the US Defence Advanced Research Projects Agency. It is thought to have received about $15 million from the venture capitalists and another $15 million by way of DARPA grants.
According to Dow Jones, Farhad Tabrizi, Grandis' CEO, said it as a "very successful exit" for the VCs. That suggests a $30-60m price was paid by Samsung.
The Grandis operation will be merged into Samsung's own research and development operation. When might product appear? It could be as early as next year but may be likelier to show its face in 2013. ®