Science —

Hybrid nano-wire memory storage device shows potential

New work that integrates nanowire technology into more conventional non- …

Nanowires and other nanomaterials have shown great promise in creating future generations of electronic devices. Given their intrinsic properties based solely on their size, a large amount of research seeks to find ways to have them replace our current technology that is based around metal oxide semiconductor field effect transistors (MOSFETs). New work from researchers at NIST, George Mason University, and Kwangwoon University in Seoul has generated a hybrid memory device that uses both conventional techniques and exploits the properties of silicon nanowires. The hybrid structure exhibited by these devices means that they are more reliable than other nanowire approaches, and they should be easier to integrate into modern components.

The hybrid device that the team built is a non-volatile memory device similar to a flash device, which retains its memory even when power is turned off. In this new device the researchers combined silicon nanowire with a high-end type of non-volatile memory known as semiconductor-oxide-nitride-oxide-semiconductor (SONOS) technology. The researchers mention that this approach would "provide a smooth transition for integrating SiNW [silicon nanowires] into viable memory devices within the well known SONOS structure." In addition to the easier integration benefits that arise, the manufacturing of these materials was also done using a clever hands-off self-alignment technique that would lower both the production and final overall costs of the device relative to the complex procedure needed to manufacture traditional flash memory cards.

The hybrid device works in a fairly simple manner.  The nanowires are grown onto an oxide-nitride-oxide substrate.  When positive voltage is applied, electrons tunnel down into the substrate; when negative voltage is applied, the electrons tunnel back into the wires. When no voltage is present, the device can be read, and the position of the electrons will represent a "1" or a "0." The authors point out that this device has many features which make it a very attractive candidate for a non-volatile memory device: it has simple read/write/erase capabilities and, more importantly, has a large memory window, which is the voltage range over which it stores information. The large memory window means that it will have a high resistance to outside voltage disturbances; an errant shock won't necessarily erase all of your memory.

The work was published in a recent issue of the journal Nanotechnology and can be read for free for the next few days. In the article the authors say that the hybrid device also shows advantages over other nanowire based memory devices, in addition to the ease of integration—which they emphasize—the devices were shown to be stable at higher temperatures than similar setups. One key piece of information that was not reported, and which probably is not known at this time, are what values of memory density could be obtained with this technology. Nanowires are used to gain the benefit of their ability to be scaled down to work in very small devices, but the work presented here was concerned with small number of SiNW ONO devices, not the millions that would be used to make up a chip in a commercial application. However, even if they are able to only match the current memory density found in commercial chips, the decreased production cost would be a welcome benefit.

You must to comment.

Channel Ars Technica