Bio-inspired nano-photodiode for Low Light, High Resolution and crosstalk-free CMOS image sensing

Abstract
Previous attempts have been devoted to mimic biological vision intelligence at the architectural system level. In this paper, a novel imitation of biological visual system intelligence is suggested, at the device level with the introduction of novel photodiode morphology. The proposed bio-inspired nanorod photodiode puts the depletion region length on the path of the incident photon instead of on its width, as the case is with the planar photodiodes. The depletion region has a revolving volume to increase the photodiode responsivity, and thus its photosensitivity. In addition, it can virtually boost the pixel fill factor (FF) above the 100% classical limit due to decoupling of its vertical sensing area from its limited planar circuitry area. Furthermore, the suggested nanorod photodiode photosensitivity is analytically proven to be higher than that of the planar photodiode. We also show semi-empirically that the responsivity of the suggested device varies linearly with its height; this important feature has been confirmed using Sentaurus simulation. The proposed nano-photorod is believed to meet the increasingly stringent High-Resolution-Low-Light (HRLL) detection requirements of the camera-phone and biomedical imaging markets. © 2011 IEEE.

Citation
Saffih, F., Fitzpatrick, N. N., Mohammad, M. A., Evoy, S., & Cui, B. (2011). Bio-inspired nano-photodiode for Low Light, High Resolution and crosstalk-free CMOS image sensing. 2011 IEEE International Symposium of Circuits and Systems (ISCAS). doi:10.1109/iscas.2011.5937686

Publisher
Institute of Electrical and Electronics Engineers (IEEE)

Journal
2011 IEEE International Symposium of Circuits and Systems (ISCAS)

Conference/Event Name
2011 IEEE International Symposium of Circuits and Systems, ISCAS 2011

DOI
10.1109/ISCAS.2011.5937686

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