Image sensor having a reduced length metal wiring connecting floating diffusion regions

An image sensor, comprising:

• a shared pixel including two sub pixels of a 1×2 structure, each of the two sub pixels sharing, through a metal wiring, at least one floating diffusion region thereon;
• unit pixels surrounding the at least one floating diffusion region, within the shared pixel, separated from each other by front-side deep trench isolation, and each including a photodiode;
• at least one transfer transistor adjacent to the at least one floating diffusion region and on each of the unit pixels;
• a first source follower transistor on a first unit pixel located in a first quadrant among the unit pixels;
• a conversion gain transistor on a second unit pixel located in a second quadrant among the unit pixels;
• a reset transistor and a selection transistor on a third unit pixel located in a third quadrant among the unit pixels;
• and
• a second source follower transistor on a fourth unit pixel located in a fourth quadrant among the unit pixels, wherein:
• the metal wiring connects the at least one floating diffusion region to a source region of the conversion gain transistor and a gate of the first source follower transistor, and
• a right angle is formed by the at least one floating diffusion region contacting the metal wiring.

An image sensor, comprising:

• a shared pixel including four sub pixels of a 2×2 structure, each of the four sub pixels sharing, through a metal wiring, at least one floating diffusion region thereon;
• unit pixels surrounding the at least one floating diffusion region, within the shared pixel, separated from each other by front-side deep trench isolation, and each including a photodiode, wherein four unit pixels are in a first row and four unit pixels are in a second row;
• at least one transfer transistor adjacent to the at least one floating diffusion region and on each of the unit pixels;
• a conversion gain transistor on one unit pixel of the first row among the unit pixels;
• and
• a source follower transistor on two unit pixels of the second row among the unit pixels, wherein:
• the metal wiring connects the at least one floating diffusion region to a source region of the conversion gain transistor and a gate of the source follower transistor, and
• an acute angle is formed by the at least one floating diffusion region contacting the metal wiring.