Conclusion
In this study, a novel centripetal collection image sensor based on FDSOI technology has been investigated. In the CCIS image sensor array, adjacent pixels in the same row share a common drain and source to avoid STI. This can make the pixel pitch shrink down to 400 nm. The key of the CCIS is using a specific electric field to realize centripetal photo-generated charges collection and crosstalk suppression. To generate the centripetal electric field, a storage well and isolation well are designed. The well structure has great impact on the CCIS performance. The isolation wells must be heavily doped to ensure crosstalk suppression. The CCIS with shallow wells can realize higher collection charge density and lower dark current. When the storage wells are completely depleted, the electric field would cover the whole storage wells, which can improve the conversion gain and suppress dark current. The CCIS can realize up to 62% quantum efficiency. According to the layout design, the fill factor of the CCIS is about 42%. The efficient photoelectric conversion and good crosstalk performance of the CCIS are demonstrated by TCAD simulation. It presents great potential for higher-resolution applications.
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Acknowledgements
This work was supported in part by National Key R&D Plan (Grant No. 2016YFA0202101) and National Natural Science Foundation of China (Grant No. 61674008).
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Liu, L., Yu, G., Du, G. et al. A centripetal collection image sensor (CCIS) based on back gate modulation achieving 1T submicron pixel. Sci. China Inf. Sci. 65, 149401 (2022). https://doi.org/10.1007/s11432-020-2933-y
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DOI: https://doi.org/10.1007/s11432-020-2933-y