Memory breakthrough is cheaper than chips

gallery

Nanotechnology has turned a bug from the 1960s into a major breakthrough in flash memory research. It is believed the technology, based on silicon dioxide and commonly found as sand or quartz, could boost memory density by up to five times.

A research team at Rice University, Texas, has produced a memory cell that uses a five nanometre – five billionths of a metre – filament of silicon dioxide. This compares with the 27 nanometre carbon wires currently in use. Apart from being smaller, the base material is also cheaper.

The nanowires have several other properties of benefit. The chips will tolerate higher temperatures than current NAND chips and will not be affected by radiation. More importantly, the new memory only requires two terminal connections, rather than three, so the nanowires will be stackable to form 3D memory chips.

"The fact that they can do this in 3D makes it highly scalable," said a spokesperson from the team. "We've got memory that's made out of dirt-cheap material and it works."

An electric charge applied to the nanowires repeatedly breaks and reconnects its crystals. These breaks are used by the chip to store digital information.

This is not a new discovery and was first observed 40 years ago, but it was dismissed at the time as a problem when using silica-based technology. Now such fine filaments can be manipulated using current tools, the bug has been turned into an asset.

Jun Yao, a graduate student on the research team, sandwiched an insulating layer of silicon oxide between semiconducting sheets of polycrystalline silicon electrodes to create the effect. He said one of his main problems was convincing the rest of the team that silicon dioxide worked better than carbon.

Email to a friend

Print this page