Non-Volatile Memory
Innovations in non-volatile memory with low latency powered by cutting edge materials and device research
Two different technologies are currently used as the memory accessed by the CPU: SRAM and DRAM. Both are volatile, meaning data stored will be lost when power fails or is turned off. A new class of memory (Persistent or Storage Class Memory, SCM) is being investigated and developed that is non-volatile, i.e., data does not disappear when power is lost.
Western Digital’s Efforts on Non-Volatile Memory
The NVM group within the Western Digital Research team is tasked with evaluation of all the candidate NVM memory cell designs.
Not only must a memory cell hold data, but it must also retain the data for a commercially acceptable time. The speed of the cell must fall into the targeted latency for SCM, and the lifetime of the cell must meet the requirements for SCM. The cell must be manufacturable using current silicon fabrication equipment, and the technology must be scalable to smaller and smaller nodes if it is to compete in the data storage market.
To accomplish this mission, the NVM team has to investigate existing and new materials, fabricate memory cells, and subsequently test those cells and characterize the cells against the target specification for an SCM NVM cell.
Promising memory cell technologies need to be optimized, no cell will meet the full specification on first examination, those cells with promise must be optimized (materials, manufacturing processes, etc.). In addition, the change in cell properties with size must be investigated to determine if the technology is scalable.
Once a suitable memory cell has been identified the NVM Research team works with other teams within Western Digital to investigate what would be required to productize the technology and use it to make a product. This requires efforts ranging from integration into an operating system to building a fab to produce the new technology.
Western Digital Nanoscale Lab
To accomplish these objectives, the Research organization has built the nanoscale lab, which is unique in storage and memory industry.
The lab has a suite of thin film deposition tools, patterning tools, characterization equipment, and modeling capabilities to fabricate, study, and develop novel materials for nanoscale devices.
These materials are then patterned and overlayed with other materials to produce nanoscale devices and test circuits, all in the same lab. Testing in another suite of electrical characterization tools completes the cycle of material development, device design, fabrication, and testing.