Over the past five years, the Arm Research team has been working to develop new types of non-volatile memory based on correlated electron materials (CeRAM). This week, the company announced that in order to concentrate its efforts on the semiconductor market, it will be transferring all of its related IP to a Cerfe Labs, an Arm spin-out company.
The Cerfe Labs is a spin-off company from Arm Research. Image used courtesy of Cerfe Labs
As part of the deal, Arm will transfer its full CeRAM IP portfolio of more than 150 patent families to Cerfe Labs that will be the foundation for a roadmap of related CeRAM technologies. Cerfe Labs will, in turn, work to develop and license new types of non-volatile memory based on both CeRAM and ferroelectric transistors (FeFETs).
In this article, we’ll take a look at CeRAM and FeFET technology to get a better understanding of the implications of this news.
CeRAM: An Overview
For the past decade, the industry has been looking to develop resistive RAM (RRAM) because of its low power and small-access latency. In this development process, researchers have turned to using transition metal oxide (TMOs), like NiO, in which “filaments” are grown at higher “electroforming” voltages and currents.
The memory scheme involves the connection and disconnection of these filaments between electrodes.
Examples of CeRAM technology. Image used courtesy of Cerfe Labs
CeRAM, on the other hand, is a resistive memory that uses TMOs without filaments and electroforming. The technology takes advantage of the fact that TMOs have incomplete 3D or 4D atomic shells, which go through quantum phase transitions involving a change of valence induced by field or voltage.
For NiO, for example, a voltage of 0.6 V is needed to write an insulating state and 1.2 V to write a conductive state. This is a promising technology for RRAM because it offers read speeds as high as 10 femtoseconds and a read voltage of 0.1 V to 0.2V, making it an extremely quick and low-power technology.
FeFETs: An Overview
FeFETs are a type of field-effect transistor that can serve as a form of non-volatile memory.
The transistor itself is of a very similar layout to a standard MOSFET: it is a three-terminal MOS device with a gate, drain, and source. The difference is that a FeFET includes a ferroelectric material located between the gate electrode and the source-drain conduction region of the device.
By applying an electric field to the gate of the device, it creates a permanent field polarization in the ferroelectric material. The result of this is a device that holds a state and maintains it even when the power is removed.
FeFET semiconductor layout. Image used courtesy of NextGenLog
It offers a promising option for non-volatile memory because its similarities to MOSFETs make it easy to understand and compatible with many existing CMOS technologies.
Cerfe Lab’s Future
Combining these two technologies could have huge benefits. Seemingly, combining the non-volatility and integrability of a FeFET with the low-power and low-latency of CeRAM offers the best of both worlds.
Eric Hennehoefer, CEO of Cerfe Labs, says, “CeRAM is the industry’s most promising non-volatile memory with characteristics not found in any other memory technology today. . . . The Cerfe Labs team is well-positioned to accelerate the work started as part of Arm Research and help CeRAM reach its potential as a low-cost, high-performance solution for improving systems that scale from edge AI to HPC.”