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Erscheinungsjahr
- 2025 (4)
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- Englisch (4)
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- CMOS (3)
- Micro-ring resonator (MRR) (2)
- Photonic sensors (2)
- Silicon on insulator (SOI) (2)
- Biomarker (1)
- Biosensor (1)
- C-reactive protein (1)
- CRP (1)
- Germanium photodiode (1)
- Local backside etching (1)
Organisationseinheit der BAM
Photonic micro-ring resonators (MRR) are widely studied for their high sensitivity across applications like environmental monitoring, healthcare, and chemical analysis. Their evanescent field sensing requires partially unembedded waveguides compatible with CMOS processing. Our approach uses local backside etching with an additional buried oxide (BOX) etch to release waveguides while preserving the back-end of line (BEOL) structure, enabling spatial separation of the sensing area and electronics. The BOX etch critically affects sensor performance, as waveguide surface roughness can alter MRR properties and coupling. We analyzed MRR design variations, comparing wet and dry etching techniques for their effects on optical performance across rib and strip waveguides in quasi-TE and quasi-TM modes. Wafer-level measurements show that backside-released MRR achieve high extinction ratios with slightly reduced quality factors, advancing high-sensitivity photonic sensors.
Photonic micro-ring resonators (MRR) are widely studied for their high sensitivity across applications like environmental monitoring, healthcare, and chemical analysis. Their evanescent field sensing requires partially unembedded waveguides compatible with CMOS processing. Our approach uses local backside etching with an additional buried oxide (BOX) etch to release waveguides while preserving the back-end of line (BEOL) structure, enabling spatial separation of the sensing area and electronics. The BOX etch critically affects sensor performance, as waveguide surface roughness can alter MRR properties and coupling. We analyzed MRR design variations, comparing wet and dry etching techniques for their effects on optical performance across rib and strip waveguides in quasi-TE and quasi-TM modes. Wafer-level measurements show that backside-released MRR achieve high extinction ratios with slightly reduced quality factors, advancing high-sensitivity photonic sensors.
The development of novel photonic integrated microchips (PIC) is a promising approach to allow for the convenient detection of key biomarkers in complex matrices through multichannel real-time analysis in a highly compact package. This study reports the successful development and application of a backside released CMOS chip designed for the multichannel real-time detection of biomarkers. Operating at the C-band at approx. 1550 nm, the microchip features three dedicated detection sensors in addition to a reference sensor, enabling simultaneous analysis of multiple biomarkers. The compact and highly miniaturized design of this microchip, with a footprint of just 1 mm², positions it as promising candidate for point-of-care diagnostics and personalized medicine applications. This technology opens a path to transform biomarker detection across various medical fields, offering rapid, reliable, and cost-effective diagnostic solutions. In conclusion, the presented multichannel photonic microchips signify a substantial leap forward in real-time biomarker detection, providing a highly capable platform for future research and clinical applications.
The integration of photonic sensors into compact systems requires space-efficient solutions, such as the backside release of waveguides on silicon-on-insulator (SOI) platforms. This study presents the design, fabrication, and characterization of fully backside-released micro-ring resonators (MRRs) using the IHP SG25H5EPIC technology. The performance of rib and strip waveguides released by either dry or wet etching of the buried oxide (BOX) layer is evaluated. While wet etching provides low-loss release of rib waveguides, dry etching is required for the release of strip waveguides but results in increased waveguide losses and reduced quality factors. The effects of these release methods on critical coupling conditions, extinction ratio (ER), full width at half maximum (FWHM), and sensor performance are analyzed. The findings confirm that both etching strategies yield structures suitable for photonic sensing, with backside release enabling co-integration with microfluidic and optoelectronic components. These results contribute to the advancement of high-performance, integrated silicon photonic sensors.
