Understanding the properties of different materials is essential for designing and manufacturing high-quality products, and during this project reliable methods for characterizing the physical and chemical properties of different materials were developed.
Integrated photodetectors were realized on top of a standard SiN wafer with 800 nm-thick SiN photonic waveguide layer, which were optimized for operation in the optical C-band. Two fabrication runs were completed, including SiN and photodetectors on the same wafer, with two process integration strategies. The fabrication process involved several critical steps such as lithography, deposition, etching, and cleaning. Each step required careful optimization and attention to detail to ensure the desired outcome was achieved.
A proof-of-concept detector working in the infrared wavelength range was demonstrated. A parametrized design of integrated photodiode test waveguides was included to enable the extraction of optical losses, responsivity, and quantum efficiency. Design and simulation of the integrated photodiode as well as the material and process developments were the main focus during the execution of this project. Integrated photodiodes were characterized using electro-optical set up as well as electrical probe stations.
During this project, the fellow was exposed to different areas of photonics integration development. The work involved deep training in optical design concepts and cases of use, as well as in opto-electrical characterization. The main focus of POTION was however, to deepen the fellow’s skills in microfabrication (Class 100 cleanroom - CMi, EPFL) as well as being exposed to 200 mm wafer processes within the framework of LIGENTEC’s established partnership with an the worldwide recognized CMOS foundry, XFAB, in France. This experience was very valuable not only for technical skills development but also for career development.
