| CPC H10F 39/80377 (2025.01) [H01L 21/76224 (2013.01); H10D 30/024 (2025.01); H10D 30/6217 (2025.01); H10D 64/513 (2025.01); H10D 64/516 (2025.01); H10D 64/518 (2025.01); H10F 39/18 (2025.01); H10F 39/802 (2025.01); H10F 39/80373 (2025.01); H10F 39/807 (2025.01); H10D 30/6211 (2025.01); H10F 39/813 (2025.01)] | 15 Claims |
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1. An image sensor, comprising:
a photodiode disposed in a semiconductor substrate having a first surface and a second surface opposite to the first surface;
a floating diffusion disposed in the semiconductor substrate;
a transfer transistor configured for coupling the photodiode to the floating diffusion, the transfer transistor comprising a vertical transfer gate extending a first depth in a depthwise direction from the first surface into the semiconductor substrate; and
a transistor coupled to the floating diffusion, the transistor comprising:
a planar gate disposed proximate to the first surface of the semiconductor substrate; and
a plurality of vertical gate electrodes, each extending a respective depth into the semiconductor substrate from the planar gate in the depthwise direction, wherein the plurality of vertical gate electrodes are configured along a channel width direction of the transistor
wherein the plurality of vertical gate electrodes comprise:
a first vertical gate electrode extending a second depth into the semiconductor substrate;
a second vertical gate electrode extending the second depth into the semiconductor substrate; and
a third vertical gate electrode extending a third depth into the semiconductor substrate, wherein the third vertical gate electrode is configured between the first vertical gate electrode and the second vertical gate electrode;
wherein the second depth is less than the third depth, and wherein the third depth is
the same as the first depth of the vertical transfer gate.
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