Current Flash solid-state storage devices have reached their physical limits, making further improvement increasingly challenging. At CEA-Leti, research engineers are constantly working to address these challenges and develop sustainable solutions.
Renzo Antonelli, a PhD candidate at CEA-Leti and the Laboratory for Microelectronics Technologies (LTM, CNRS), has made remarkable advances in his research, titled “Reading reliability in 1S1R OTS+PCM devices based on Double-Patterned Self-Aligned structure". His work, presented at the European Symposium on Reliability of Electron Devices, Failure Physics and Analysis (ESREF), focuses on the reliability of Phase-Change Memories (PCM), with Ovonic Threshold Switching (OTS) selector, commonly referred to as “Crossbar arrays".
After graduating in electronic engineering at the Polytechnic University of Turin, Renzo joined Leti to pursue a PhD following his master's internship. His dissertation, “Phase-Change Memory and OTS Selectors: A Challenge for the Future of Computing", led him to explore the materials, architecture, and reliability of advanced memory devices.
Crossbar Memory Array: A subject of innovation
The 3D Crossbar memory represents a promising solution for the future of storage, featuring smaller and faster cells. This technology relies on thermodynamics: the PCM transitions between crystalline and amorphous states of the material through Joule heating. Renzo conducted electrical tests on the memory devices, focusing on their reliability upon reading. Though scientific literature about the reading operation in a Crossbar remains limited, Renzo managed to evaluate the impact of the PCM and the OTS selector on the stored information. His findings prove that reading operations have an impact on stored data, which led him to propose possible solutions to mitigate the issue. Renzo received an award for both his findings, and his paper's didactic approach, which includes a reproducible experimental protocol for other research groups.
“At the conference, I had the opportunity to speak with experts from diverse fields. It taught me more about industries I previously know little about.”
This achievement is just the beginning: Renzo continues his work on memory reliability as part of his thesis. His next goal is to understand the impact of thermodynamics on these memories to identify the physical properties critical to this technology.