Fast optical chip interconnects with graphene technology from Germany

The European Union (EU) and private investors are investing a total of 254.4 million euros in the young Aachen-based company Black Semiconductor. Its name refers to the black color of coal, as the super-thin material graphene with special electrical and optical properties is a modification of carbon.

Black Semi wants to build a pilot production facility for fast optoelectronic components made of graphene on 300-millimeter wafers. The aim is to integrate optical interconnects with graphene technology into "normal" CMOS logic chips such as processors, systems-on-chip (SoCs) and computing accelerators: Co-integrated Optics (CIO). This should enable powerful and energy-efficient chip-to-chip communication, even over longer distances.

Co-founder Dr. Daniel Schall has been researching graphene optoelectronics for many years and also worked for the Gesellschaft für Angewandte Mikro- und Optoelektronik mbH (AMO GmbH), which operates the Advanced Microelectronic Center Aachen (AMICA). Black Semiconductor was spun off from AMO GmbH in 2019.

Optical chip-to-chip interconnects

Other companies are also working on closely coupling CMOS logic chips and optical interconnects. Intel has been reporting progress in silicon photonics, i.e., optoelectronics implemented in silicon technology, for around 20 years.

A few months ago, Nvidia CEO Jensen Huang pointed out the disadvantages of converting electrical signals into optical signals and explained that this is why copper cables were previously used for the fast networking of AI clusters via NVLink. The integration of optical interconnects directly into logic chips could significantly increase the energy efficiency of optical interconnects in practice.

Chiplets are another approach for connecting optical transceivers to CMOS chips. Some companies are also working on optical processors.

(ciw)