Optimized Integrated PIN Photodiodes with Improved Backend Layers
This paper constitutes a systematic analysis of the impact of low- doped intrinsic base material, different bottom anti-reflective coatings and dielectric filter deposition on the electrical and optical performance of Si photodiodes processed in standard CMOS fabrication processes. Photodiode design...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
IFSA Publishing, S.L.
2019-09-01
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| Series: | Sensors & Transducers |
| Subjects: | |
| Online Access: | https://sensorsportal.com/HTML/DIGEST/september-october_2019/Vol_237/P_3112.pdf |
| Summary: | This paper constitutes a systematic analysis of the impact of low- doped intrinsic base material, different bottom anti-reflective coatings and dielectric filter deposition on the electrical and optical performance of Si photodiodes processed in standard CMOS fabrication processes. Photodiode designs cover full area as well as interdigitated variants. Optimization of the photodiode’s spectral responsivity for a specific wavelength has been achieved by different bottom anti-reflective coating concepts as well as direct deposition of interference filters on Si-wafer. While standard bottom anti-reflective coating is the most efficient way of optimizing the optical response, embedded bottom anti-reflective coating offers the possibility of additional interference filter deposition directly on the wafer. For full area photodiodes with respective anti-reflective coating in place, the photodiode’s quantum efficiency approaches 100 % for l=750 nm. For interdigitated photodiodes, the spectral responsivity in the wavelength range of 400 nm to 500 nm can be significantly enhanced compared to full area photodiodes and show values as high as 0.21 A/W @ 400 nm and 0.37 A/W @ 500 nm. Optimized blue photodiodes are not sensible to iEPI thicknesses and have a leakage current of 10 pA for a 150 µm ´ 150 µm square photodiode. |
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| ISSN: | 2306-8515 1726-5479 |