R&D: “Holy Grail” With Invention of Universal Computer Memory

From Lancaster University

The device could replace the $100 billion market for DRAM, which is the ‘working memory’ of computers, as well as the long-term memory in flash drives

A new type of computer memory which could solve the digital technology energy crisis has been invented and patented by Lancaster scientists.

The electronic memory device – described in research published in Nature Scientific Reports – promises to transform daily life with its ultra-low energy consumption.

In the home, energy savings from efficient lighting and appliances have been completely wiped out by increased use of computers and gadgets, and by 2025 a ‘tsunami of data’ is expected to consume a fifth of global electricity.

But this new device would immediately reduce peak power consumption in data centres by a fifth.

It would also allow, for example, computers which do not need to boot up and could instantaneously and imperceptibly go into an energy-saving sleep mode – even between key stokes.

The device is the realisation of the search for a ‘Universal Memory’ which has preoccupied scientists and engineers for decades.

Manus Hayne, physics professor,Lancaster University, said: “Universal Memory, which has robustly stored data that is easily changed, is widely considered to be unfeasible, or even impossible, but this device demonstrates its contradictory properties.”

A US patent has been awarded for the electronic memory device with another patent pending, while several companies have expressed an interest or are involved in the research.

The inventors of the device used quantum mechanics to solve the dilemma of choosing between stable, long-term storage and low-energy writing and erasing.

While writing data to DRAM is fast and low-energy, the data is volatile and must be continuously ‘refreshed’ to avoid it being lost: this is clearly inconvenient and inefficient. Flash stores data robustly, but writing and erasing is slow, energy intensive and deteriorates it, making it unsuitable for working memory.

Professor Hayne said: “The ideal is to combine the advantages of both without their drawbacks, and this is what we have demonstrated. Our device has an intrinsic data storage time that is predicted to exceed the age of the Universe, yet it can record or delete data using 100 times less energy than DRAM.”

The research has been funded by EPSRC through an Impact Acceleration Account and the Future Compound Semiconductor Manufacturing Hub (EP/P006973/1), the Joy Welch Educational Charitable Trust, and IQE plc. It has recently gained EC funding from the ATTRACT project aimed at breakthrough technologies (Grant Agreement 777222).

Article: Room-temperature Operation of Low-voltage, Non-volatile, Compound-semiconductor Memory Cells

Nature Scientific Reports has published an article written by Ofogh Tizno, Andrew R. J. Marshall, Department of Physics, Lancaster University, Lancaster, LA1 4YB, UK,Natalia Fernández-Delgado, Miriam Herrera, Sergio I. Molina, Department of Material Science, Metallurgical Engineering and Inorganic Chemistry,and IMEYMAT, University of Cádiz, 11510, Puerto Real, Cádiz, Spain, and Manus Hayne, Department of Physics, Lancaster University, Lancaster, LA1 4YB, UK.

Abstract: “Whilst the different forms of conventional (charge-based) memories are well suited to their individual roles in computers and other electronic devices, flaws in their properties mean that intensive research into alternative, or emerging, memories continues. In particular, the goal of simultaneously achieving the contradictory requirements of non-volatility and fast, low-voltage (low-energy) switching has proved challenging. Here, we report an oxide-free, floating-gate memory cell based on III-V semiconductor heterostructures with a junctionless channel and non-destructive read of the stored data. Non-volatile data retention of at least 10⁴ s in combination with switching at ≤2.6 V is achieved by use of the extraordinary 2.1 eV conduction band offsets of InAs/AlSb and a triple-barrier resonant tunnelling structure. The combination of low-voltage operation and small capacitance implies intrinsic switching energy per unit area that is 100 and 1000 times smaller than dynamic random access memory and Flash respectively. The device may thus be considered as a new emerging memory with considerable potential.“