Interview: Refined ReRAM enters the storage wars

August 30, 2017 // By William Wong
Technology Editor of Electronic Design, Bill Wong, talks with Crossbar’s Sylvain Dubois about how the company is rethinking storage innovation in IoT, AI, mobile computing, and data centres.

New non-volatile memory technologies have significant challenges because flash memory is so well established. That’s not stopping the competition, though, and one of these may eventually replace flash memory as we know it. Crossbar’s ReRAM (resistive RAM) is one of those technologies.

 

I talked with Sylvain Dubois, Vice President of Strategic Marketing & Business Development, to find out more about ReRAM and how it compares to other technologies like Intel’s Optane.

 

How does ReRAM work?

Sylvain Dubois replies, “The fundamental physics behind ReRAM cells (Fig. 1) are incredibly simple, making it easy to stack cells in 3D and scale to very small process nodes. The cells typically employ a switching material with different resistance characteristics sandwiched by two metallic electrodes. The resistance switching mechanism is based on the formation of a nanofilament in silicon-based switching material. Designers have substantial flexibility to optimize performance depending on the switching materials and memory-cell organization."

 

 

Figure 1. The resistance switching mechanism of Crossbar's technology is based on the formation of a filament in the silicon-based switching material when a voltage is applied between the two electrodes.

 

"Regardless of the material specifics, developers of ReRAM technology all face several common challenges: overcoming temperature sensitivity, integrating with standard CMOS technology and manufacturing processes, and limiting the effects of “sneak path” currents, which would otherwise disrupt the stability of the data contained in each memory cell.

 

Crossbar ReRAM technology is based on a simple two-terminal device structure using CMOS-friendly materials and standard CMOS manufacturing processes. When an electric field is applied across the cell, a metallic filament forms across the cell and changes its resistive characteristics. Because the switching mechanism is based on an electric field, the cell behaviour is very stable across a wide temperature range.

 

It can be easily integrated with CMOS logic circuitry and manufactured using existing CMOS fabs without the need for any special equipment or