4DS Renews IMEC Contract for Perovskite ReRAM Targeting AI

Founded in 2007, 4DS has been at the forefront of memory technology advancements. The company embarked on a groundbreaking journey in 2017 by collaborating with IMEC to develop an interface switching ReRAM. This partnership marked a significant milestone in the industry, as reported by eeNews Europe. Additionally, 4DS entered into a joint development agreement with Western Digital subsidiary HGST, solidifying its position as a key player in the field of memory innovation.

The core of 4DS's revolutionary ReRAM lies in its utilization of a perovskite crystalline material known as praseodymium, calcium, manganese, and oxygen (PCMO) in a cross-point, two-terminal device. This unique design enables the memory to achieve fast write times comparable to DRAM, coupled with an impressive endurance of 3 x 10^9 cycles. The company claims that the non-volatile persistence of the memory can be finely tuned, ranging from hours to weeks.

Termed as a "ReRAM that breathes," 4DS's technology operates by facilitating the transition between high- and low-resistance states through the movement of oxygen ions within an interfacial layer triggered by an electronic pulse. Setting itself apart from other ReRAM technologies, 4DS emphasizes that the ion movement in its PCMO device occurs uniformly across the entire cross-point area. The company highlights the scalability of the programming current with the cross-point area as evidence of this unique mechanism.

By leveraging oxygen presence to determine the conductivity of the cell, 4DS achieves a SET state when oxygen is present and a RESET state when oxygen is removed. The involvement of the entire interface area ensures that the current density remains minimal, contributing to the exceptional endurance of the memory cell, as claimed by the company.

In a recent financial report for the half-year ending on December 31, 2023, 4DS showcased promising results with an IMEC megabit array test platform featuring 60nm memory cells. Despite a net loss of AU$1.78 million, the company generated sales revenue of AU$165,007 during the same period. Technical achievements included a single-shot write time of 4.7ns, enabling low-energy per bit writing at DRAM speeds.