Vertical overflow drain combined with vertical transistor

An image sensor system, comprising:

• a plurality of pixels disposed in a semiconductor material positioned to receive light through a backside of the image sensor and generate image charge, wherein each pixel in the plurality of pixels includes:
• a photodiode disposed in a semiconductor material;
• a pinning layer disposed in the semiconducting material and coupled to the photodiode;
• a vertical overflow drain disposed in the semiconductor material, the vertical overflow drain in contact with the pinning layer and coupled to the pinning layer such that the pinning layer is disposed between the vertical overflow drain and the photodiode;
• a floating diffusion disposed in the semiconductor material proximate to the photodiode;
• and
• a vertical transfer transistor disposed in part in the semiconductor material and coupled to the photodiode to transfer the image charge from the photodiode to the floating diffusion in response to a transfer signal applied to a gate terminal of the vertical transfer transistor;
• and
• readout circuitry coupled to the plurality of pixels to readout the image charge from the plurality of pixels;
• and
• control circuitry coupled to the plurality of pixels to control operation of the plurality of pixels.