Patent ID: 8773562

Claim:
An image sensor for an electronic device, comprising: a photodiode chip comprising: at least one photodiode for receiving light; a transfer gate extending vertically from a top surface of the photodiode chip; a transistor array chip in communication with the photodiode chip and vertically stacked on the photodiode chip, the transistor array chip comprising: a floating diffusion node in communication with the at least one photodiode; a reset gate in communication with the at least one photodiode; a source follower gate in communication with the floating diffusion node; and a row select gate in communication with the source follower gate and the floating diffusion node; and a logic chip operably vertically stacked on the transistor array chip and in communication therewith; wherein the transfer gate communicates data from the at least one photodiode to the transistor array chip and is connected to the transistor array chip, wherein the transfer gate comprises: a semiconductor transfer channel; an oxide layer surrounding an outer perimeter surface of the transfer channel; a polysilicon layer at least partially surrounding an outer perimeter surface of the oxide layer; and a metal layer in communication with the transfer channel, wherein the transfer channel extends vertically from the to surface of the photodiode chip and the metal layer communicatively connects the transfer gate to the transistor array chip; and the logic chip selectively activates the vertical transfer gate, the reset gate, the source follower gate, and the row select gate.