IBM working on spinning magnetic memory

IBM has linked with Japan's TDK to develop so-called spin torque transfer RAM or STT-RAM.

In STT-RAM, an electric current is applied to a magnet to change the direction of the magnetic field. The direction of the magnetic field (up-and-down or left-to-right) causes a change in resistance, and the different levels of resistance register as ones or zeros.

Under the current plan, IBM and TDK, an integral player in magnetic recording components for hard drives, will develop a 65-nanometre prototype within the next four years.

Grandis, a Silicon Valley start-up, is also trying to commercialise STT-RAM. Grandis is making samples for potential customers in its current facility and hopes to hit the market late next year.

Previously, IBM had been working on a more conventional type of magnetic memory called MRAM. However, the company has been having trouble shrinking the transistors on these chips.

Bill Gallagher, senior manager of exploratory non-volatile memory at IBM, said: "As you make that device smaller [MRAM], you need to increase the magnetic field, and to continue to write [data], it becomes impractical. To scale beyond 65-nanometre, we have to find a new mechanism to write information."

The 65-nanometre process is currently used to make processors, though most other chips are made on older processes such as 90-nanometre or even 13-nanometre. IBM has made MRAM prototypes but on older manufacturing processes.

IBM has not released MRAM chips commercially. Freescale Semiconductor has released MRAM chips commercially but has recently expressed doubt about the technology's longevity. Speaking at the recent Flash Memory Summit, Freescale's David Bondurant said MRAM "may not go beyond" 65 nanometres.

STT-RAM and phase-change memory are probably the two leading candidates of non-volatile memory to go commercial in the future, Gallagher said. STT-RAM is faster but phase change is denser.

STT-RAM may also last longer, he said. In phase-change memory, microscopic bits on a chip are heated up to several hundred degrees Celsius. Heating changes the crystalline material to amorphous. The difference on how the host computer interprets the crystalline and amorphous surfaces is registered as a one or a zero in the computer.

Intel and STMicroelectronics have worked extensively in phase change. Some sources in the memory business believe that the joint venture between the two, Numonyx, will soon announce plans on how it intends to bring phase change memory to market. (Phase change has been discussed as a memory technology since 1970 but has not yet come to market.)

Why does IBM care about memory chips when it makes its money mostly from services and servers? Big Blue also makes chips and licenses intellectual property. Developing non-volatile memory will give it a necessary ingredient for making chips for itself or others.

Gallagher said: "You can't make a system on a chip without some kind of non-volatile memory."

Michael Kanellos writes for CNET News.com