A recent study has shed light on how next-generation electronics, particularly memory components in computers, deteriorate over time.
A recent study conducted by researchers at the University of Minnesota Twin Cities has provided valuable insights into the degradation of next-generation electronics, including computer memory components. Gaining a better understanding of these degradation processes could enhance the efficiency of data storage solutions.
The findings were published in ACS Nano, a peer-reviewed scientific journal, and are highlighted on the cover of this issue.
As technology in computing evolves, there is an increasing need for more efficient data storage methods. Spintronic magnetic tunnel junctions (MTJs) — tiny devices that leverage electron spin to enhance hard drives, sensors, and other microelectronic systems, including Magnetic Random Access Memory (MRAM) — appear to be promising contenders for future memory technologies.
MTJs serve as foundational elements for non-volatile memory in devices like smartwatches and facilitate in-memory computing, potentially leading to improved energy efficiency in artificial intelligence applications.
Utilizing an advanced electron microscope, the researchers examined the nanopillars inside these systems, which are minuscule, transparent layers within the device. By enabling a current to flow through the device, they were able to observe its operation. In doing so, they watched how the device deteriorated and ultimately failed in real-time.
“Conducting real-time transmission electron microscopy (TEM) experiments can be quite difficult, even for seasoned researchers,” explained Dr. Hwanhui Yun, the lead author and postdoctoral research associate in the University of Minnesota’s Department of Chemical Engineering and Material Sciences. “However, after numerous challenges and improvements, we were able to consistently produce functioning samples.”
This process revealed that, over time, the continuous flow of current causes the layers within the device to become pinched, leading to malfunctions. While earlier studies had proposed this idea, this marks the first time that researchers have been able to directly observe the occurrence. Once a “pinhole” (the pinch) forms in the device, it signals the onset of degradation. As the team continued to increase the current, the device ultimately melted and completely ceased to function.
“What was notable about this discovery is that we identified this burnout at a significantly lower temperature than what was previously believed possible,” remarked Andre Mkhoyan, a senior author and professor as well as Ray D. and Mary T. Johnson Chair in the Department of Chemical Engineering and Material Sciences at the University of Minnesota. “The observed temperature was nearly half of what had been estimated earlier.”
Upon examining the device at an atomic level, the researchers recognized that materials at such a small scale exhibit different properties, including varied melting points. Consequently, this indicates that the device will fail at a much earlier point than previously understood.
“There has been a strong need to comprehend the interfaces between layers in real-time under actual operating conditions, such as applying current and voltage, but no one has been able to achieve this depth of understanding until now,” noted Jian-Ping Wang, another senior author and a Distinguished McKnight Professor in the Department of Electrical and Computer Engineering at the University of Minnesota.
“We are pleased to report that our team has uncovered findings that will directly influence the design of the next generation of microelectronic devices for the semiconductor industry,” Wang added.
The researchers aspire that this newfound knowledge will be applied in the future to enhance the design of computer memory units, aiming to extend their lifespan and increase efficiency.
Along with Yun, Mkhoyan, and Wang, the research team included Deyuan Lyu, a postdoctoral researcher in the Department of Electrical and Computer Engineering at the University of Minnesota, research associate Yang Lv, former postdoctoral researcher Brandon Zink, and researchers from the University of Arizona’s Department of Physics.
This research was financed by SMART, one of the seven centers of nCORE, a program of the Semiconductor Research Corporation supported by the National Institute of Standards and Technology (NIST); University of Minnesota Grant-in-Aid funding; National Science Foundation (NSF); and the Defense Advanced Research Projects Agency (DARPA). The study was carried out in partnership with the University of Minnesota Characterization Facility and the Minnesota Nano Center.
