Many of the components in today’s smartphones have changed rapidly over the last few years. ARM processors have gone from single core units running at less than 1GHz to octa-core power houses running at twice the clock frequency. Displays have moved from low resolution 480 x 800 units (or even less) to Ultra HD. Camera’s likewise have gone from around 3MP to 16MP. But what about internal storage? There is no doubt that it has increased from humble devices with less than 1GB of usage flash memory to today’s 64GB behemoths, but there hasn’t been a revolution. Until now that is…
Researchers at Rice University have released details about their work on a new type of Resistive RAM (RRAM). Their new material, which uses porous silicon oxide, reduces forming voltage, improves manufacturability and can be fabricated at room temperature using conventional production methods. In other words, it is cheaper to make and gives higher yields.
The key idea behind RRAM is the use of a dielectric material (one that won’t normally conduct electricity) which is inserted between two wires. When a sufficiently high voltage is applied across the wires, a narrow path forms through the dielectric material. This means the cell can be either “on” or “off” just like a switch, or in computer terms it can be a 1 or a 0.
According to Rice University, RRAM is expected to replace current flash memory technologies within a few years. RRAM specialist Crossbar has announced plans for RRAM prototype chips that store about one terabyte on a chip the size of a postage stamp. That is more than 50 times the current data density found in today’s flash memory.
Rice’s new RRAM uses silicon oxide as its dielectric component. Silicon is the most abundant element on Earth, and probably the most studied. It is the most basic ingredient in conventional microchips. In 2010 a research team, led by chemist James Tour, discovered how to create conductive filament pathways in silicon oxide. This then opened the door for the material to be used for RRAM.
If the chemists are to be believed RRAM is the future. “It can be manufactured at room temperature, has an extremely low forming voltage, high on-off ratio, low power consumption, nine-bit capacity per cell, exceptional switching speeds and excellent cycling endurance,” said James Tour.
The new fabrication technique has already got the attention of a several manufacturers who are interested in licensing the technology. Hopefully this means that in the next couple of years we can say good-bye to flash memory and say hello to 1TB of RRAM!