Uniformly bridged gradient time-of-flight photodiode for image sensor pixels

Abstract

A uniform bridge gradient (UBG) time-of-flight (ToF) photodiode block is described, e.g., for integration with image sensor pixels. The UBG ToF photodiode block can be part of a UBG ToF pixel, and the image sensor can include an array of such pixels. Each UGB ToF photosensor block has a plurality of taps for selective activation, and a photodiode region for completing and rapidly transporting photo-carriers through the plurality of taps when photo-carriers are generated. Embodiments of the photodiode region include a photodiode-defining implant, a relatively shallow first bridge implant, and a relatively deep second bridge implant. The bridge implants provide a lateral bridge with a uniform doping gradient near and across the plurality of taps.

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