Black Semiconductor GmbH, a startup that plans to make chip-to-chip interconnects from graphene, has secured €254.4 million in funding to support its research.

The investment was disclosed today. Black Semiconductor, a spinout from RWTH Aachen University in Germany, said that the bulk of the capital was provided by Germany’s federal government and the state of North Rhine-Westphalia. About a tenth of the funding, or €25.7 million, came from an investor consortium led by Porsche Ventures and Project A Ventures.

Black Semiconductor also counts about a half-dozen other venture capital firms among its backers. The investor group includes Onsight Ventures, a fund affiliated with Arm Holdings plc co-founder Hermann Hauser.

Data center servers currently transmit data between their internal components in the form of electric pulses sent over copper wires. Black Semiconductor is developing technology that will allow data to be sent in the form of light, which travels faster than electricity over copper. The faster information can travel to a server’s chip, the sooner processing may begin, which speeds up calculations.

Black Semiconductor is one of several startups developing optical chip-to-chip interconnects. What sets the company apart is that its interconnect will be based on graphene, a form of carbon that is drawing significant interest among researchers. The material has several physical properties that could potentially lend themselves well to semiconductor production.

Under a microscope, graphene is a sheet of carbon measuring one atom thick. The carbon atoms are arranged in hexagons that connect to one another at the edges. Being a crystal, graphene is not printed or assembled but rather grown, usually on a base layer that is made of another material such as copper.

Chips such as central processing units process data in the form of electricity. As a result, that electricity has to be turned into light before it can be sent over an optical interconnect such as the one Black Semiconductor is developing. Once the light reaches the chip to which it’s sent, it must be turned into back electricity before processing can begin. Black Semiconductor says that its interconnect will implement the component responsible for those tasks using graphene.

Graphene is highly effective at both conducting electricity and transmitting light. It has no band gap, a physical property that interferes with the movement of electrons, and absorbs only 2.3% of incoming light. The remaining 97.7% of photons can pass through, a feature that could potentially be useful for optical data transmission tasks.

The company says its interconnect will “co-integrate optics with electronics.” There are several ways to integrate optical and silicon components. The traditional approach is to place the two component collections on the same motherboard. A newer, more efficient technique known as co-packaged optics allows optical hardware to be integrated directly into a processor.

Black Semiconductor believes its technology could be used to boost artificial intelligence servers’ performance. According to the company, transmitting data as light between a server’s chips can speed up processing and increase power efficiency. Black Semiconductor argues that graphene-based interconnects could  likewise enhance the performance of cars’ onboard computing modules.

The investment announced today will enable the company to quadruple its headcount to 120 employees by 2026. That year, Black Semiconductor also plans to launch a prototype manufacturing facility in Aachen. The plan is to start mass producing graphene-based interconnect components by 2031. 

“As traditional chip technology moves closer to its technological and economic limits, our innovation paves the way for faster, more powerful, cost-efficient, and energy-efficient computation,” said Black Semiconductor co-founder and Chief Executive Officer Daniel Schal (pictured, right, with co-founder Sebastian Schall.)

Researchers are currently exploring whether graphene could be used to optimize the movement of data not only between chips, but also inside them.

Information-carrying electric pulse travel between a processor’s transistors over tiny embedded wires that were historically made of copper. As part of their efforts to boost processor performance, chipmakers have had to make those wires thinner, which increases the risk of hardware faults. Some scientists have suggested that the wires inside chips could be coated with a layer of graphene, which is 200 stronger than steel, to boost their durability. Other research teams are exploring ways of making entire chips from graphene.

Photo: Black Semiconductor