HP discovers memristor mechanism
May 17, 2011 // R. Colin Johnson
Electrical engineers who expressed skepticism that Hewlett Packard Co.'s memristors could switch as fast as DRAM and yet retain their memories millions of times longer than flash can now rest easy, according to their inventor, senior HP Fellow Stanley Williams.
"What we have discovered is that an electric field and a current act together to enable a memory device that can both be switched very rapidly and hold its state indefinitely," said Williams. "Not only does an applied voltage drive the migration of oxygen vacancies in the device, but at the same time there is a current that heats it up to about 300 degrees Celsius—just enough to turn the amorphous film into a crystalline film."
Memristors are touted as the future "universal memory" device because they are as fast as DRAM, as small as flash, and as durable as read-only-memories, according to HP. As the fourth fundamental passive circuit element—after resistors, capacitors and inductors—memristors retain either a high- or low-resistance state by virtue of introducing or removing oxygen vacancies in oxide thin films.
Synchrotron x-rays probed the memristor in a 100 nanometer region with concentrated oxygen vacancies (right, shown in blue) where the memristive switching occurs. Surrounding this region a newly developed structural phase (red) was also found to act like a thermometer revealing how hot the device becomes when read or written.
Using their favorite formulation—titanium oxide—HP recently used high-energy synchrotron x-rays to correlate the device's electrical characteristics with its atomic structure, chemistry, and temperature in three dimensions. The until now unforeseen conclusion was that a hot spot near the bottom electrode heats enough during switching to induce a crystallization of the oxide. After driving out vacancies (for a 1) or introducing them (for a 0) in one-to-two nanometers thick region, the film cools in an annealing-like like process which leaves the film in a fixed crystalline state that should remain that way indefinitely.
"In testing, we have switched these devices over 30 billion times and counting, with no degradaton in their ability to retain information," said Williams.
HP is currently working with Hynix Semiconductor Inc., to create commercial memories based on memristive technology. All news
Delayed roadmap set for debut at TSensors Summit
November 27, 2015
The MEMS and Sensors Industry Group has announced that it will release the outline of the TSensors (Trillion Sensors) Roadmap ...
Tower buys Maxim's Texas wafer fab
Deterministic motor control with FPGAs
Smart buildings, smartphones will drive IR detector market
Private ID as a service leverages smartphone-enabled biometrics
Like Micron, SK Hynix rejects Chinese advances
November 26, 2015
Korean memory chip company SK Hynix has rejected an investment offer from China's state-backed Tsinghua Unigroup, according ...
NXP, Freescale merger clears FTC hurdle
Thin film micro-lenses stretch to focus
German battery maker puts squeeze on Tesla's solar storage plans
- Battery Size Matters
- Software-Defined Radio Handbook - 11th edition
- Multichemistry Buck Battery Charger Controller
- Automotive Circuit Protection using Littelfuse Automotive TVS Diodes
InterviewCEO interview: InvenSense's Abdi on expanding MEMS horizons
InvenSense Inc. is a MEMS company that has epitomized a fabless approach to a sector that is still highly reliant on a thorough grasp of the manufacturing and packaging processes. We interviewed CEO Behrooz ...
Filter WizardCheck out the Filter Wizard Series of articles by Filter Guru Kendall Castor-Perry which provide invaluable practical Analog Design guidelines.
Linear video channel
READER OFFERRead more
This month, FTDI Chip is giving away six MCU development board packages complete with a dedicated compiler (including a full integrated development environment).
Worth Euro 315 each, the packages include a credit card sized Clicker 2 board for the FT90X 32-bit MCU supplied alongside a powerful dedicated compiler from MikroElektronika.
MORE INFO AND LAST MONTH' WINNERS...
December 15, 2011 | Texas instruments | 222901974
Unique Ser/Des technology supports encrypted video and audio content with full duplex bi-directional control channel over a single wire interface.