Sense organs for our digital helpers

“Siri – Do I have to bring an umbrella today?”. “Alexa, show me what that makeup looks like on me!” The digitization of our everyday life is progressing unstoppably and at a rapid pace. New devices and features that we marveled at yesterday as technical wonders are already being used regularly today – and the next major innovations are already in the starting blocks. We still have to do most of the housework ourselves are not flying to work with “jetpacks” yet. But individual tasks at home, such as vacuuming and window cleaning, are already being performed in many places by specialized robots – and even networked, pilotless air taxis suddenly no longer seem to be pure science fiction.

Self-learning systems and artificial intelligence are a part of this. They are technologies that can open up revolutionary applications for us. But these systems can only ever be as good as the sensors with which they perceive their environment.

"Sensors are the sensory organs of the machines, their eyes, noses and ears."

"Sensors are the sensory organs of the machines, their eyes, noses and ears," explains Prof. Dr. Michael Heuken, Vice President of Corporate Research and Development at AIXTRON and Professor at RWTH Aachen University. "They provide the raw data that the algorithms use to get an idea of the world; these sensors are the basis on which they make decisions and which allow them to do what the user expects from them."

In 3D thanks to highly compact lasers

Lasers such as VCSEL are central components of these advanced "sensory organs" – optical sensor systems that open the door to a multitude of completely new applications. The acronym VCSEL stands for "Vertical Cavity Surface Emitting Laser" and describes the principle of emitting light extremely precisely bundled and vertically from the surface of a chip. A large number of such very small VCSELs create a precise dot pattern on objects. The resulting reflections are measured and interpreted by a camera. The system delivers fascinatingly precise three-dimensional models of objects. This 3D sensor technology is used, for example, in the automotive industry to provide assistance systems, to provide autonomously controlled vehicles with lightning-fast images of current road conditions, to detect obstacles or to measure distances.

Thanks to their ultra-compact design, optical sensor systems that work with VCSEL are even used in mobile devices such as smartphones, e.g. for identifying users using facial recognition. Applications that scan bodies or rooms are also conceivable – as a database for virtual changing rooms or for applications that require dimensioning functions.

The production process: Made in Germany

Very few users who are fascinated by these many new possibilities today, e.g. for the current generation of mobile devices, know that a large part of the foundation for this technology comes from the Aachen region:

One essential foundation for the production of VCSEL devices is the MOCVD ("Metal Organic Chemical Vapor Deposition") manufacturing process, in the development and marketing of which AIXTRON has been significantly involved for more than 30 years. Unlike silicon-based microchips, in MOCVD technology several different elements of Groups III and V of the periodic table are applied to a substrate to achieve the desired properties. AIXTRON has developed the so-called planetary reactor for this highly complex process, with its extreme demands on precision and quality.

"The chamber for the separation of the materials is the heart of our Planetary Reactor® technology."

"The chamber for the separation of the materials is the heart of our Planetary Reactor® technology," says Prof. Dr. Heuken. “This is where the coating process requested by the customer takes place – depending on the specific requirements to be met by the compound semiconductors to be produced."

Inside the chamber, semiconductor layers are applied to the carrier material – the so-called wafers – at temperatures that can be up to 1,600 degrees, depending on the starting material. The materials required for the coating process are introduced into the center of the chamber in a gaseous state and extracted by a pump at the edge so that they flow straight and evenly over the hot wafers to the edges of the chamber. The chemicals break up and only the desired atoms diffuse through the gas phase onto the surface of the wafer – well-sorted with atomic layer over atomic layer.

"The performance of the finished laser components depends decisively on this first production step," explains Prof. Dr. Heuken. "Our MOCVD process ensures the high quality of compound semiconductors and thus the quality and reliability of the subsequent application technology."

"Our MOCVD process ensures the high quality of compound semiconductors and thus the quality and reliability of the subsequent application technology."

Where are things headed now?

"Augmented Reality" – the expansion of our perception of the world through information and digital elements – or immersion in completely artificial worlds ("Virtual Reality") are technologies that are about to cross the threshold to the mass market. And precise environmental sensors and powerful light sources are indispensable for these application scenarios. In professional use, such as medicine and product design, they have long since become established tools. VCSEL technology makes it possible to capture the visible world in such detail and in three dimensions so a real fusion of reality and the digital world becomes possible instead of simply superimposing virtual objects on the real environment.

Worldwide, startups as well as established, globally operating corporations are working on innovations that use VCSEL as a core technology for new application scenarios. The 3D sensors inspire the imagination of the developers. Better focusing methods for film and photography, interpretation of human facial expressions for recognizing states of mind, and countless other ideas that we have not even ventured to think of yet: The potential of VCSEL systems for consumer electronics as well as for tasks in research, technology and development can hardly be overestimated. Thanks to the wide range of applications offered by 3D sensor technology, demand in a wide variety of industries is growing steadily.

So we may soon be playing squash in our own living room with a virtual ball bouncing off the real wall of the room. Or we may treat ourselves to a digital pet that makes itself comfortable on our real sofa, jumps onto shelves and interacts with us in an amazingly real way. Alternative user interfaces, such as non-contact yet highly precise control of devices and software through gestures, are also conceivable thanks to 3D sensor technology.

The triumphant advance of 3D sensors based on VCSEL technology has only just begun – and remains exciting: AIXTRON will continue to dedicate itself with passion to the evolution of the manufacturing process and the continuous development of numerous other innovative components. True to the company motto: Our technology. Your future.

MOCVD – the details