Low power consumption, highly sensitive silicon photonic optical detectors

Silicon photonics is a fast-growing technology, addressing many applications such as data communication, sensing, imaging, and metrology to name a few. By leveraging the mature Complementary Metal Oxide Semiconductor (CMOS) processes used in electronics, high-volume and high-yield Photonic Integrated Circuits (PICs) can be fabricated at a relatively low cost. Among the major building blocks in a PIC, the on-chip photodetector (PD) is critical in the conversion of optical power from a PIC to a corresponding electrical signal. Integrating Ge on a silicon photonics platform is now widely deployed, as it is compatible in Si-based large-scale fabrication with good bandwidth and responsiveness. However, further integration of Ge is limited due to its indirect bandgap and small absorption coefficient, high dark currents and limited wavelength detection range, preventing applications in longer wavelengths. Integration of III-V materials such as GaAs, InP, GaSb and others on a silicon photonics platform at scale can overcome these limitations, with lower dark currents and utilising higher and more versatile absorption wavelengths suitable for a broad range of applications from near to mid-infrared.

Imec has been working on the development of Ge-on-Si (A)PDs and monolithic III – V photodetectors, with applications in data centres and telecommunications. The objective of the PhD is to research III-V photodetectors and avalanche photodetectors integrated on silicon photonics, to create small, highly sensitive and highly scalable photodetectors on a chip with low power consumption on imec’s 200 mm and 300 mm platforms.

What you will do

The course of the PhD will be divided into three phases. Firstly, you will work on a literature survey to obtain existing up-to-date knowledge of PD and APDs. Secondly, you will assess the validity of proposed devices and proof-of-concept (PoC) by using suitable simulation tools, driven by target requirements and fabrication limitations, and arbitrate design variations in proposed layouts. Finally, the last phase consists of characterisation, data analysis and feedback to future design proposals. At the end of the PhD, the candidate will gather strong knowledge not only on device physics, modelling, and characterisation but also on process integration, layout design, teamwork and scientific communications.

Expectation of workload

Literature study (10%), design modelling (20%), simulation (30%), layout (10%), characterization (30%)

What we do for you

We offer you the opportunity to join the world’s leading research centre in nanotechnology at its headquarters in Leuven, Belgium. You will become part of a future team that makes the impossible possible. Together, we shape the technology that will define the society of tomorrow. We are committed to being an open multicultural and informal working environment.

Who you are

• You hold an MSc degree in the following fields: Photonics, Applied Physics, Electrical Engineering, and Optical Engineering.
• You have a strong interest in Photonics and a strong background in semiconductor physics.
• Autonomy, scientific curiosity, and ability to work in an international environment.
• Hands-on exposure to photonic modelling software (e.g., Lumerical, Rsoft).
• Desirable programming and scripting skills. Experience with Python is a plus.
• Experience with version control systems such as Git and GitHub is a plus.