Is there a hope for digital immortality? Use silicon carbide to store data perma

With the development of the internet, social media, and artificial intelligence, the amount of data generated globally every day is surging. Computers have an increasingly urgent need for new storage technologies, which require new technologies to have extremely high storage density and the ability to store data long-term and securely.

An international research group led by the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) has now proposed a new technology that uses the characteristics of atomic-level defects in silicon carbide semiconductor materials for long-term data storage.

The research team reported in the journal "Advanced Functional Materials" that these defects, created by a focused ion beam, have high spatial resolution, fast writing speed, and low energy consumption for storing individual bits.

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Rapidly growing data

In 2012, global data exceeded 1 zettabyte (ZB, 2^70 bytes), marking the arrival of the zettabyte era. According to the latest estimates, the internet now generates about 3.3 million terabytes (TB) of new data daily, growing exponentially, with a 90% increase in global data in just the past two years.

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It is projected that by 2025, the annual data production will reach over 100 ZB. The energy consumption of data centers accounts for about 1% of global electricity production and is expected to increase to 3% to 13% by 2030. Existing storage technologies such as magnetic storage, optical discs, and solid-state drives have limitations in terms of storage density and long-term storage.

Moreover, current data storage media have a shelf life, and data migration needs to be carried out every few years for data security. If storage technology does not change, in the future, we will not only be trapped in perpetual data migration operations but will also consume a large amount of energy in the process.02

Physical Laws Constrain the Upper Limit of Storage

Currently, magnetic storage devices are the preferred solution for large-capacity data storage, but physical laws limit the upper bound of storage density. To increase storage density, it is necessary to reduce the size of magnetic particles.

However, doing so makes the impact of thermal fluctuations and diffusion processes in the material on storage life significant and cannot be ignored. Adjusting the magnetic properties of the material can suppress this impact, but at the cost of consuming more energy.

Similarly, the performance of optical storage is also constrained by physical laws. The diffraction limit of light requires that the minimum record bit width cannot be less than half the wavelength of light, which sets the limit for optical storage.

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Silicon Carbide May Be a Near-Term Solution

Silicon carbide has silicon vacancy defects at the atomic scale, meaning that some lattice sites lack silicon atoms. These defect sites can emit light under electron beam or laser excitation, and at room temperature, these defects can be maintained for over 10 million years, making them highly suitable for long-term data storage.

Researchers use focused proton or helium ion beams to actively introduce defects into silicon carbide, and read information using cathodoluminescence or photoluminescence, which has the advantages of high spatial resolution, fast writing speed, and low energy consumption per bit storage.In order to store more data within a limited volume, they utilized gray coding and multi-layer storage technology. By employing focused ion beams of varying energies to create silicon vacancy defects of different densities in silicon carbide, they used these defects to emit light of varying brightness corresponding to different data information. They adopted an 8-bit gray coding, which means that each storage unit is no longer just 0 and 1. With gray coding, more information can be stored within a finite space.

They fabricated silicon carbide into 50nm thick films and stacked them in multiple layers. By controlling the lateral position and depth, as well as the number of defects, they achieved 4D data encoding. Currently, they have achieved stacking 10 layers without inter-layer interference.

Silicon carbide storage technology is essentially a form of optical storage technology, and the storage units must also be no smaller than half the wavelength. Researchers replaced the laser with a focused electron beam of shorter wavelength, thereby improving spatial resolution. The current silicon carbide storage density is 10 layers × 75 Gbit/in², which is 750 Gbit/in², comparable to current optical storage data. With an electron beam, a storage density of 300 Gbit/in² per layer can be achieved, surpassing the current magnetic storage records, although it consumes more energy.

The greatest advantage of this storage technology is the longevity of data preservation. The lifespan of silicon carbide storage decreases at high temperatures; it can maintain for 9,000 years at 100°C and can be preserved for 11 million years at 22°C.