- Anzeige -
read time: min
Si-based CMOS imagers to detect SWIR wavelengths above 1µm

Nov 15, 2019 | Allgemein, Topstory

Thin-film photodetectors

Si-based CMOS imagers to detect SWIR wavelengths above 1µm

Thanks to a cross-departmental effort involving material development, semiconductor processing skills, system-level design and much more, imec has realized breakthroughs in the capabilities of silicon-based CMOS imagers to detect short-wave infrared (SWIR) wavelengths above one micrometer.

Figure 1 | By processing a thin-film multilayer stack with photoactive layer sensitive in the infrared range (r.), on top of a Silicon readout circuitry (ROIC), Imec creates an IR-sensitive CMOS imager (l.) that’s compatible with mass manufacturing. (Image: Imec)

Such wavelengths (e.g. the 1450nm and 1550nm bands) are important for the development of applications such as computer vision in mobile devices. Yet, due to optical limitations, these wavelengths are normally invisible to Si-based devices. Conventional approaches that use III-V materials (e.g. InGaAs) can overcome this detection barrier, but are not available at an acceptable price point for consumer devices. Thanks to thin-film photodetector (TFPD) technology, Imec has now developed an end-to-end solution that enables Si-based infrared CMOS sensors at the price level of conventional CMOS imagers. TFPD are multilayer stacks of a few hundred nanometers overall thickness with one of the layers being sensitive to IR. By post-processing these onto a Si-CMOS readout circuit, Imec combines the best of both worlds: infrared detection via a CMOS-compatible process flow. Regarding materials suitable for this thin film, the company is investigating multiple options, ranging from polymer- and small-molecule organic materials to inorganic colloidal quantum-dot layers. The latter, for the moment, is most promising because of the tunable and low-energy bandgap inherent to quantum dots. So far, Imec has built most of its prototypes and demonstrators with PbS quantum-dot materials. The quantities of lead being used remain well within the legal restrictions of the EU ROHS guidelines and other regulations, making them suitable for production. Completely lead-free alternatives are on the roadmap and being investigated as well.

Pages: 1 2Auf einer Seite lesen

Ph.D. Paweł E. Malinowski, Program Manager User Interfaces & Imagers; Ph.D. David Cheyns, Team Leader Future Interactive Thin-Film Technology; Ph.D. Pierre Boulenc, Leader Pixel Devices Team, Imec
www.imec-int.com

Topstories

News

this may also interest you

inVISION at home

Special events require special reactions. To ensure that you always have access to the current issue even during the Corona pandemic and that you can read our trade journals in your home office (or any other place), TeDo Verlag provides you with the upcoming issues of its trade journals free of charge as an eMagazine.

Fingers Crossed

Probably none of us imagined March 2020 at the beginning of the year like this.

Who’s next?

Unfortunately, the coronavirus currently has the trade fair landscape firmly under its control.

Access to AI

Meanwhile more and more users have made their first experiences with AI.

OPC UA Specification for Joining Technologies

The leading manufacturers of assembly systems have decided to develop an OPC UA Companion Specification (CS) for joining technologies with the VDMA Robotics + Automation Association.

DGQ Quality Day

DGQ Quality Day For the sixth time, the Deutsche...