Researchers developing phase-change memory devices for more powerful computing

February 6, 2018, Yale University
A Promising Computer Technology Advances

A collaboration between the lab of Judy Cha, the Carol and Douglas Melamed Assistant Professor of Mechanical Engineering & Materials Science, and IBM's Watson Research Center could help make a potentially revolutionary technology more viable for manufacturing.

Phase-change memory (PCM) devices have in recent years emerged as a game-changing alternative to computer random-access memory. Using heat to transform the states of material from amorphous to crystalline, PCM chips are fast, use much less power and have the potential to scale down to smaller chips – allowing the trajectory for smaller, more powerful computing to continue. However, manufacturing PCM devices on a large scale with consistent quality and long endurance has been a challenge.

"Everybody's trying to figure that out, and we want to understand the behavior precisely," said Yujun Xie, a PhD candidate in Cha's lab and lead author of the study. "That's one of the biggest challenges for ."

The work of the Yale-IBM research team could help clear this hurdle. Using in situ transmission electron microscopy (TEM) at the Yale Institute for Nanoscience and Quantum Engineering (YINQE), they observed the device's phase change and how it "self-heals" voids - that is, empty spaces left by the depletion of caused by chemical segregation. These kinds of nanoscale voids have caused problems for previous PCM devices. Their results on self-healing of voids are published in Advanced Materials.

The standard PCM device has what's known as a mushroom structure, while the Yale-IBM team used a confined PCM structure with a metallic lining to make it more robust. "The metallic liner protects the material and reduces the resistance drift of the PCM, improving the whole performance," Xie said.

By observing the phase-change process through TEM, the researchers saw how the PCM device's self-healing properties come from a combination of the device's structure and the metallic lining, which allow it to control the phase-change of the material.

Wanki Kim, an IBM researcher who worked on the project, said the next step is possibly to develop a bipolar operation to switch the direction of voltage, which can control the chemical segregation. In normal operation mode, the direction of voltage bias is always the same.  This next step could prolong the lifetime even further.

Explore further: Ultralow power consumption for data recording

More information: Yujun Xie et al, Self-Healing of a Confined Phase Change Memory Device with a Metallic Surfactant Layer, Advanced Materials (2018). DOI: 10.1002/adma.201705587

Related Stories

Ultralow power consumption for data recording

January 25, 2018

A team of researchers at Tohoku University, in collaboration with the National Institute of Advanced Industrial Science and Technology (AIST) and Hanyang University, has developed new phase change material with electrical ...

The '50-50' chip: Memory device of the future?

September 13, 2013

A new, environmentally-friendly electronic alloy consisting of 50 aluminum atoms bound to 50 atoms of antimony may be promising for building next-generation "phase-change" memory devices, which may be the data-storage technology ...

Controlling the stiffness of a material at the nanoscale

February 24, 2017

Using a needle far thinner than a human hair, scientists revealed how to control mechanical stiffness in a promising material. The team applied an electric field with a nano-sized needle to cause a reversible change in the ...

Recommended for you

Targeting 'hidden pocket' for treatment of stroke and seizure

January 19, 2019

The ideal drug is one that only affects the exact cells and neurons it is designed to treat, without unwanted side effects. This concept is especially important when treating the delicate and complex human brain. Now, scientists ...

Artificially produced cells communicate with each other

January 18, 2019

Friedrich Simmel and Aurore Dupin, researchers at the Technical University of Munich (TUM), have for the first time created artificial cell assemblies that can communicate with each other. The cells, separated by fatty membranes, ...

Using bacteria to create a water filter that kills bacteria

January 18, 2019

More than one in 10 people in the world lack basic drinking water access, and by 2025, half of the world's population will be living in water-stressed areas, which is why access to clean water is one of the National Academy ...

Hand-knitted molecules

January 18, 2019

Molecules are usually formed in reaction vessels or laboratory flasks. An Empa research team has now succeeded in producing molecules between two microscopically small, movable gold tips – in a sense as a "hand-knitted" ...

This computer program makes pharma patents airtight

January 17, 2019

Routes to making life-saving medications and other pharmaceutical compounds are among the most carefully protected trade secrets in global industry. Building on recent work programming computers to identify synthetic pathways ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.