Highly integrated optical sensors project successfully completed

Verena Vescoli, Senior Vice President R&D at ams, said: “Thanks to Horizon2020 funding from the European Union and superb collaboration from all partners in the HIOS Consortium, we’ve been able to drive market innovation at a far faster rate than would have otherwise been possible. This is a great example of how European companies can work together to compete on the world stage supported by the European Union.”

From personal mobile device to wearables smart homes, offices, cars, and more, people are surrounded by sensors. Sensor functionality is evolving rapidly, from making our phones more intuitive and lighting solutions more intelligent to conserving battery power and enabling breakthrough medical technologies. 

Sensors therefore play a key role in many applications in markets including mobile and consumer, automotive, and industrial. One thing is constant across these fields: the challenging demand for high performance, such as high sensitivity or low power consumption, often in combination with small size and low cost. However, this drives the need for sensor integration with electronics and other system components which can be highly complex to achieve.

The Highly Integrated Optoelectronic Sensor Consortium 

The HIOS Consortium addressed this need for collaborative innovation in the growing market for intelligent light sensors. In particular, HIOS developed and launched the world’s first light sensor with fully integrated optical stack including multiple filters and an aperture replacing multiple discrete components. 

The sensor in 3D technology, IC filter and Wafer Level Optics integration technology developed in the HIOS project is also expected to bring further cost-efficient, very small, and high-performance sensors to the market. ams established a high-volume production environment for 3D/Through Silicon Via (TSV) process technology which has now been extended by equipment and processes for on-chip inorganic optical filters and wafer level molding to form on-chip optical components.

HIOS’ ambitious goal was to develop an industry-leading class of new optical sensor products offering the highest possible integration of components and miniaturisation. Departing from the initial concept for an Ambient Light Sensor, the project focused on enabling the later launch of a colour sensor as an achievable target. 

To reach this shared goal, all partners had to push the boundaries of capabilities in their fields while cooperating seamlessly at the same time. 

Bühler Leybold Optics developed and enhanced new equipment for advanced optical interference filter processing and announced its new deposition tool for high performance optical coating, HELIOS Gen II, in February 2019. This is the latest version of its highly-successful sputter tool with improved layer distribution and enhanced low particle process. 

New hardware and PARMS+ process lead to a tighter specification with high productivity and yield. Boschman successfully established a new level of accuracy with its molding tool and process development for optical packaging applications being capable to form diffusor layers, lenses and apertures.

All these developments were successfully demonstrated for implementation on the ams family of ambient light sensors products. Based on the excellent quality of the interference filters developed throughout this project, new spectral colour sensor products could be designed covering applications from UV, visible and infrared wavelengths.

In 2018, a first colour sensing product was launched delivering the first engineering samples for a miniaturised 18 channel (3x6) spectral sensor family AS7265x.

Given interest in these new highly-integrated sensing applications, ams successfully launched the AS7341 colour sensor, an 11-channel spectrometer for spectral identification and colour matching applications, in January 2019. 

With eight optical channels, this sensor enables new spectral sensing functions for mobile devices covering the whole visible range from UV to near infrared. With an additional three extra channels for Clear, NIR and Flicker it also allows exact determination of 50Hz or 60Hz ambient light flicker to minimise distortion of ambient light sources.