A man works at his terminal at the Range Operations center of the Royal Australian Air Force (RAAF) Woomera Range Complex in Woomera in South Australia on Friday, ahead of the Japan Aerospace Exploration Agency (JAXA) Hayabusa 2 probe's expected sample drop to earth after landing on and gathering material from an asteroid some 300 million kilometers from Earth. Photo: AFP / Morgan Sette

NanoBridge Semiconductor (NBS), a Japanese venture company, has announced a series A preferred stock issue to NEC Corporation, Japan Industrial Partners and other companies valued at approximately ¥130 million ($1.25 million at ¥104/$).

Series A refers to an early stage of fundraising. The funds will support the further development of NanoBridge atomic switch technology in applications which require resistance to radiation, such as aerospace and communications infrastructure.

NBS is also working on NanoBridge devices for use in automotive electronics, the IoT (internet of things) and other businesses, aiming for sales of ¥5 billion ($48 million) in 2025.

NanoBridge(R) is a registered trademark of NEC.

The NanoBridge is a resistive switch, connected or disconnected by applying negative or positive bias voltages which cause a nanometer-scale copper bridge to be precipitated or dissolved in a solid electrolyte placed between copper and ruthenium electrodes in an integrated circuit.

Developed over the past 20 years by NEC and Japan’s National Institute for Materials Science, NanoBridge atomic switches are non-volatile, meaning that they do not require power to maintain an On or Off status. Circuit non-volatility is an effective way to reduce power consumption in electronic devices and systems.

Because they consume less power, and because they are highly resistant to both radiation and extreme temperatures, Nanobridge switches are well-suited to rewritable field programmable gate Aarrays (FPGAs) and non-volatile memory used  in hostile environments from autos to outer space.

An FPGA is an integrated circuit designed to be configured by the user after manufacturing. A device is said to be field-programmable if its firmware can be modified in the field. Firmware is the software that controls the device’s hardware. A gate array is a semiconductor chip in which most of the transistors have no predetermined function. 

NEC first demonstrated a NanoBridge FPGA in 2011. A practically short design time was announced in 2015. Sample production began in 2016, followed by preparations for volume production on 300mm silicon wafers. The development of NanoBridge non-volatile memory began in 2018.

In 2019, the NanoBridge FPGA was tested in the Innovative Satellite Technology Demonstration 1 spacecraft launched by the Japan Aerospace Exploration Agency (JAXA). This device was one-third the size and used only one-tenth the power of standard SRAM-type FPGAs. SRAM (static random-access memory) devices are also susceptible to malfunction caused by radiation.

“The cross-link created by metal atoms in the NanoBridge is free from the impact of electrical charges generated by the delivery of radiation,” said a 2017 NEC press release. “Accordingly, the possibility of [accidental] rewriting is extremely remote … even in a space environment that is exposed to a large amount of radiation.”

NEC is a key partner of JAXA, having provided the ion engines for the Hayabusa and Hayabusa2 space probes. Hayabusa2 is scheduled to deliver a capsule of samples from the asteroid Ryuga to the Woomera Test Range in South Australia on Sunday, December 6.

NBS was spun off from NEC in 2019 in order to expand its shareholder base and drive its growth as an independent business. The second major shareholder, Japan Industrial Partners (JIP), is a private equity fund management company headquartered in Tokyo.

As JIP Director Richard Dyck puts it in a press release this week: “The discovery of the atomic switch, based on the movement of atoms rather than electrons, was a major breakthrough in basic science. The team at NanoBridge, after two decades of skilled and focused engineering, has transformed this breakthrough into the realm of practical application.”

He also notes that the NanoBridge atomic switch can now be produced economically and in volume using standard semiconductor production equipment.

Spacecraft applications are important for science and national security, but commercial viability is likely to depend on sales to the auto and industrial markets.

The timing looks good for resilient low-power programmable AIoT terminals employing Nanobridge FPGAs and nonvolatile memory. AIoT – a combination of artificial intelligence and the internet of things – combines AI, 5G telecom and the processing of big data.

Scott Foster is an analyst with Lightstream Research, Tokyo.