Weebit’s ReRAM: A Quantum Leap in Emerging Memory Technology.
Weebit’s Resistive Random Access Memory (ReRAM or RRAM) is an emerging Non-Volatile Memory (NVM) technology that addresses the need for higher-performance, more reliable, lower-power, and more cost-effective NVM in a wide range of electronic products.
The semiconductor industry is on an ever-forward march to manufacture chips in smaller and smaller process geometries, enabling companies to reap the cost and power benefits of continued scaling while meeting ever-increasing performance requirements. Unfortunately, embedded Flash memory technology is unable to scale to the most advanced process nodes along with the rest of the chip. Weebit’s highly-scalable ReRAM technology is an ideal alternative: easily beating Flash on key metrics including cost, power consumption, endurance, access time, and more.
In addition, ReRAM offers the advantage of being a Back-End-of-Line (BEOL) technology. This is especially important for analog designs manufactured in larger/older process nodes which often require low-density, high-endurance embedded NVM. Flash is integrated in the Front-End-of-Line (FEOL) alongside many other components that are also integrated in FEOL – often forcing compromises that lead to lower performance, larger size, and higher cost. Since ReRAM is integrated in BEOL, there is no need for compromise.
How Weebit’s ReRAM Works
At a basic level, ReRAM is a memristor technology. In a memristor, resistance can be programmed (resistor functionality) and the data that is programmed into it can be stored (memory functionality). Data in ReRAM is programmed/encoded as binary information through the regulation of an electric current.
Weebit’s disruptive ReRAM cell is comprised of a thin metal oxide switching layer between two electrodes. In an initial, one-time, forming step, a positive voltage is applied to an electrode, which reversibly changes the resistance of the oxide layer to a low resistance state (LRS). During this process, a conduction filament of oxygen vacancies is formed through the oxygen ions. This increases the flow of current in one direction and decreases it in the other direction.
The level remains intact – maintaining the data – until the cell is purposefully reset by applying a negative voltage to break the filament, thus migrating to a High Resistive State (HRS). Applying positive and negative voltages can cause the cell to switch from one state to the other, encoding the binary information by creating either a 1 (LRS) or a 0 (HRS) data store in the memory cell.
Thanks to its simple structure, a ReRAM cell is small, fast, and easy to stack, and it consumes extremely low power. The key industry challenge in ReRAM technology development to-date has been in choosing the appropriate resistive material that enables changes to its chemical or physical structure and is then able to restore that structure in a repeatable, low-variability and cost-effective manner.
Weebit’s ReRAM technology – developed with R&D partner CEA-Leti – overcomes these challenges and is designed with unique benefits that make it the best NVM in its class in terms of cost, performance and reliability.
Learn more about Weebit’s ground-breaking ReRAM in Technical Resources.