Saturday, July 13, 2024

Ultra-Low Switching Current Phase-Change Memory On A Flexible Substrate

- Advertisement -

Researchers from Stanford University have overcome a key obstacle that has limited widespread adoption of phase-change memory.

As cloud-based applications and big data platforms have increased, the need for data storage infrastructure increases linearly, and as a result, power consumption increases significantly.  In past decades, researchers and scientists have searched for faster, more energy-efficient data storage technologies for everything from large data centers to mobile sensors and other flexible electronics. Among the most promising data storage technologies, phase-change memory  is thousands of times faster than conventional hard drives but uses a lot of electricity.

Phase-change memory is a type of non-volatile random-access memory which takes advantage of rapid heat-controlled changes in the material’s physical property between amorphous and crystalline states. A typical phase-change memory consists of a compound of three chemical elements—germanium, antimony and tellurium (GST)—sandwiched between two metal electrodes.

- Advertisement -

In phase-change memories, the 1s and 0s represent measurements of electrical resistance in the GST material. A high-resistance state 0, and a low-resistance state 1. The resistance states can switch from 1 to 0 and back again in nanoseconds using heat from electrical pulses generated by the electrodes.

Heating to about 300 degrees Fahrenheit turns the GST compound into a crystalline state with low electrical resistance. At about 1,100 F, the crystalline atoms become disordered, turning a portion of the compound to an amorphous state with much higher resistance.

But switching between states typically requires a lot of power, which could reduce battery life in mobile electronics. To address this issue, researchers from Stanford University have designed a phase-change memory cell that operates with low power and can be embedded on flexible plastic substrates commonly used in bendable smartphones, wearable body sensors and other battery-operated mobile electronics.

However, many flexible substrates lose their shape or even melt at around 390 F. Researchers discovered that a plastic substrate with low thermal conductivity can help reduce current flow in the memory cell, allowing it to operate efficiently. 

“Our new device lowered the programming current density by a factor of 10 on a flexible substrate and by a factor of 100 on rigid silicon,” said Eric Pop, a professor of electrical engineering and senior author of the study. “Three ingredients went into our secret sauce: A superlattice consisting of nanosized layers of the memory material, a pore cell—a nanosized hole into which we stuffed the superlattice layers—and a thermally insulating flexible substrate. Together, they significantly improved energy efficiency.”

The research has been published in the journal Science.



Unique DIY Projects

Electronics News

Truly Innovative Tech

MOst Popular Videos

Electronics Components