TORONTO — With the automotive market presenting potential opportunities of ever-emerging memories such as ferroelectric RAM (FRAM), magnetoresistive RAM (MRAM), and resistive RAM (ReRAM), Adesto Technologies is working hard to make sure that the latter makes the grade.
It recently unveiled new research demonstrating the potential of ReRAM for high-reliability applications such as automotive. The research was led by Adesto Fellow Dr. John Jameson, who shared the results at the ESSCIRC-ESSDERC 48th European Solid-State Device Research Conference earlier this month, and indicates that ReRAM could become a widely used, low-cost, and simple embedded non-volatile memory (eNVM) because it uses simple cell structures and materials that can be integrated into existing manufacturing flows with as little as one additional mask.
While Adesto was one of the first companies to bring commercial ReRAM devices to market with its trademarked CBRAM technology that consumes less power, requires fewer processing steps, and operates at lower voltages as compared to conventional embedded flash technologies, ReRAM still faces integration and reliability challenges, which the researchers tackle in their paper.
Adesto’s research indicates that ReRAM could become a widely used, low-cost, and simple embedded non-volatile memory (eNVM) because it uses simple cell structures and materials that can be integrated into existing manufacturing flows with as little as one additional mask.
“Towards Automotive Grade Embedded ReRAM,” is authored by Jameson and a dozen collaborators and will be published on the IEEE Xplore website. It describes an improved subquantum conductive bridging RAM (CBRAM) cell, whose reliability appears robust enough for automotive applications, and discusses the main types and levels of errors observed in the new cell stack. The researchers also outline the reliability models that were developed to predict endurance and storage lifetimes.
ReRAM has long been considered a natural successor to embedded Flash (eFlash) for MCUs and SoCs, note the researchers, as it uses simple cell structures and materials that can be integrated into an existing logic back-end-of-line (BEOL) using as few as one additional mask and few, if any, alterations to the front-end-of-line (FEOL), unlike eFlash, which requires 10 or more additional masks as well as a coordinated FEOL/BEOL integration scheme capable of accommodating its high thermal budget.
Another compelling reason to use ReRAM in embedded applications such as automotive is that eFlash is starting to encounter limitations as to how far it can shrink, said Adesto CTO Gideon Intrater. In a telephone interview with EE Times, he said that there’s a lot of room for shrink with CBRAM. “The big question is: Can that technology be executed simply for the automotive industry with the high standards? That’s what this paper is trying to show — that we can actually build products that will have the right level of quality for the automotive industry.”