Silicon Nanowires Upgrade Data Storage Devices

Silicon-based computing technology seems to have reached the maximum limit of miniaturization and everyone is waiting for its successor. Now, a team of researchers claims to be able to revive the veteran of computer chips and even improve its capabilities, using a new hybrid technology.

A joint team of researchers at the National Institute of Standards and Technology and Kwangwoon University in Korea, produced a new memory device that uses both silicon nanowires and a classical technology used in data storage.

This hybrid device is more reliable than pure nanowire-based devices and easier to integrate into current commercial applications. It's a "non-volatile" memory, which doesn't lose the stored information when power is interrupted. The most widely used non-volatile memory storage devices are the digital camera memory cards and the USB memory sticks.

The new technique integrates nanowires into a high-end non-volatile memory device, similar to flash, in fact a layered structure called semiconductor-oxide-nitride-oxide-semiconductor (SONOS) technology. Using a hands-off self-alignment technique, the nanowires are positioned onto the devices, a process simpler and much cheaper than the one used in today's flash memory cards.

The nanowires are grown onto a layered oxide-nitride-oxide substrate, then a positive voltage is applied across the wires, which makes the electrons in the wires to tunnel down into the substrate, thus charging it. The electrons are forced to tunnel back up into the wires using a negative voltage.

This process is actually the functioning principle of the device's memory function: each nanowire device stores a single bit of information when fully charged, a "0" or a "1" depending on the position of the electrons and the information can be read when no voltage is applied.

By combining the enhanced properties of silicon nanowires with the existing technology, this device used the best in the two techniques, thus being extremely promising for non-volatile memory applications.