Patent ID: 9312401
Filing Date: 2016-04-12
CPC Classification: H01L

Claim Text:
1. An imaging sensor system, comprising: a first semiconductor layer of a first wafer; a single photon avalanche diode (SPAD) imaging array including a plurality of pixels formed in the first semiconductor layer, wherein the plurality of pixels include an N number of pixels, wherein substantially an entire thickness of the first semiconductor layer of each pixel is fully depleted such that a multiplication region included in each pixel near a front side of the first semiconductor layer is configured to be illuminated with photons through a back side of the first semiconductor layer and through the substantially entire thickness of the fully depleted first semiconductor layer; deep n type isolation regions disposed in the first semiconductor layer between the pixels to isolate each one of the plurality of pixels from one another; a second semiconductor layer of a second wafer bonded to the first wafer; a plurality of digital counters formed in the second semiconductor layer and electrically coupled to the SPAD imaging array, wherein the plurality of digital counters includes at least N number of digital counters, wherein each of the N number of digital counters are coupled to count output pulses generated by a respective one of the plurality of pixels.